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WORKS  TRANSLATED  BY 
J.  BISHOP   TINGLE,  Ph.D., 

PUBLISHED  BY 

JOHN  WILEY  &  SONS. 


Determination  of  Radicles  in  Carbon  Compounds. 

By  Dr.  H.  Meyer,  Imperial  and  Royal  University, 
Prague.  Authorized  Translation  by  J.  Bishop 
Tingle,  Ph.D.,  F.C.S.  Third  American  Edition, 
Revised  and  Enlarged.  i2mo,  iv+2i8  pages, 
cloth,  $1.25  net. 

Spectrum  Analysis. 

By  John  Landauer,  Member  of  the  Imperial  Ger- 
man Academy  of  Naturalists.  Authorized  English 
Edition  by  J.  Bishop  Tingle.  8vo,  x  +  239  pages, 
44  figures,  cloth,  $3.00. 

Application  of  Some  General  Reactions  to  Investi- 
gations in  Organic  Chemistry. 

By  Dr.  Lassar-Cohn,  Professor  of  Organic  Chem- 
istry at  the  University  of  Konigsberg.  Authorized 
Translation  by  J.  Bishop  Tingle,  Ph.D.  12010, 
vii  -f-  ioi  pages,  cloth,  $1.00. 


DETERMINATION    OF   RADICLES 


IN 


CARBON  COMPOUNDS. 


BY 


DR.   H.    MEYER, 

Professoi  at  the  Imperial  and  Royal  German  University,  Prague, 


AND 


J.  BISHOP    TINGLE,  PH.D.,  F.C.S., 

Professor  of  Chemistry  at  McMaster  University,  Toronto,  Canada. 


THIRD   EDITION,   REVISED. 
FIRST  THOUSAND. 

s 

TM£ 

UNIVERSITY   ) 

oi-  7 

'  'FOHN\^-.X 
NEW  YORK: 

JOHN   WILEY  &  SONS. 
LONDON:  CHAPMAN  &  HALL,  LIMITED. 
1908. 


8ENERAL 


Copyright,  1899,  1903,  1908, 

BY 

J.  BISHOP  TINGLE. 


Hubert  Brummnni*  an& 


PREFACE  TO  THE  THIRD  EDITION. 


WHEN  the  call  for  the  third  edition  of  this  book  was 
received  the  question  at  once  arose  as  to  whether  it 
would  be  better  to  reset  the  pages  entirely,  or  to  place 
the  new  matter  at  the  end,  in  the  appendix.  The  latter 
course  was  adopted  for  the  following  reasons:  It  appears 
to  be  desirable,  at  present,  to  retain  almost  all  of  the 
text  of  the  second  edition.  Those  familiar  with  the 
earlier  issues  of  the  book  would  find  it  more  convenient 
to  be  able  to  turn  directly  to  the  new  material  instead 
of  having  to  disentangle  it  from  the  old.  The  adop- 
tion of  the  plan  mentioned  will  not  involve  any  special 
inconvenience  to  new  users  of  the  work,  because  copious 
cross-references  have  been  provided.  The  main  body 
of  the  book  has  been  revised  for  the  elimination  of 
typographical  errors  and  of  statements  which  investiga- 
tion has  shown  to  be  incorrect,  and  a  few  references 
to  recent  publications  have  been  inserted. 

The  new  matter  contained  in  the  appendix  has  increased 
the  total  text  of  the  book  by  about  35  per  cent.  A  good 
deal  of  care  has  been  taken  to  bring  the  contents  of 
the  volume  up  to  date,  and  it  is  hoped  that  no  important 
method  has  been  omitted.  It  may  not  be  improper  to 

iii 

175012 


IV  PREFACE. 

call  attention  to  the  fact  that  the  work  involved  in  the 
revision  of  even  a  small  book  of  this  character  is  very 
considerable,  and  the  difficulties  which  have  to  be  over- 
come are  numerous.  The  mass  of  literature  to  be  dealt 
with  is,  of  course,  immense,  and  no  two  people  would 
make  quite  the  same  selection  of  material  from  it.  A 
further  special  source  of  trouble  arises  from  the  fact 
that  a  quantitative  method  for  the  determination  of 
some  particular  group  is  frequently  worked  out  by  an 
investigator  incidentally,  as  it  were,  to  some  other  re- 
search. In  such  cases  the  results  of  the  investigation 
are  usually  published  under  a  title  which  gives  no  indi- 
cation that  the  paper  in  question  contains  a  description 
of  such  a  method  of  analysis.  It  is  obvious  that  in  these 
circumstances,  material  which  is  well  suited  for  a  book 
of  the  nature  of  the  present  one  may  be  overlooked. 

It  is  only  fair  to  Professor  Meyer  to  explain  that  the 
present  writer's  work  on  the  first  edition  consisted  in 
translating  and  rearranging  the  German  text,  to  which 
he  added  a  few  extra  paragraphs.  About  two-thirds 
of  the  new  matter  in  the  second  edition  was  contributed 
by  the  writer,  who  is  entirely  responsible  for  the  selection 
of  the  material  in  the  present  issue  and  for  the  manner 
of  its  presentation. 

J.  BISHOP  TINGLE. 

MCMASTER  UNIVERSITY, 

TORONTO,  CANADA,  April,  1908. 


PREFACE  TO  SECOND  EDITION. 


THE  usefulness  of  this  little  book  has  been  shown 
by  the  comparatively    quick  exhaustion  of  the    first 
edition.     The  present  issue  has  been   thoroughly  re- 
vised by  Dr.  Meyer  and   the  writer,  the  whole  work 
has  been  reset,  and  more  than  twenty  per  cent,  of  new 
matter  added,  including  several  figures.       The  addi- 
tions are  generally  distributed,  but  attention  may  be 
called  to  the  new  alternative  processes  for  the  determi- 
nation of  alkyls  and   carbonyl.      The  methods  which 
are  given  for    the  determination   of  the  nitroso    and 
methylene    groups    have     been     described    since    the 
publication  of  the  former  edition.      For  the   selection 
of  the  additions  Dr.  Meyer  and  the  writer  are  almost 
equally  responsible.      In  deference  to  the  wish  of  one 
or  two  reviewers  the  author  and  subject  indices  have 
been  combined.      It  is  hoped  that  this  issue  may  prove 
to  be  even  more  useful  than  the  former  one  ;  the  writer 
will    be    grateful    for    any  suggestions  or  corrections 
tending  towards  this  end.      Thanks  are  due  to  Prof. 
W.  A.  Noyes,    of    the    Rose    Polytechnic    Institute, 
Terre    Haute,   Ind.,  and    to    Dr.   A.    Tingle,    of    the 
University  of  Toronto,  Canada,  for  revising  the  proof- 
sheets. 

J.  BISHOP  TINGLE. 

ILLINOIS  COLLEGE,  JACKSONVILLE,  ILL., 
January,  1903. 


AUTHOR'S  PREFACE. 


THIS  English  edition  of  my  li  Anleitung  zur  quanti- 
tativen  Bestimmung  der  organischen  Atomgruppen  " 
has  been  prepared  by  Dr.  J.  Bishop  Tingle,  to  whom  I 
am  greatly  indebted  for  the  care  he  has  bestowed  on 
it.  I  have  endeavored  to  bring  it  into  conformity 
with  the  present  state  of  the  science  by  various  cor- 
rections and  additions.  It  has  been  further  improved 
by  certain  changes  in  arrangement  which  Dr.  Tingle 
has  made,  and  he  has  also  added  various  notes.  The 
present  edition  is  thus  a- decided  advancement  on  the 
German  one,  and  I  trust  that  in  its  new  form  it  may 
gain  many  new  friends  whilst  retaining  its  old  ones. 

Dr.  HANS  MEYER. 

PRAGUE,  October  1899. 

vii 


TRANSLATOR'S    PREFACE   TO   THE 
FIRST  EDITION. 


THE  success  of  the  German  edition  of  Dr.  Meyer's 
book  was  only  one  of  the  reasons  that  led  to  the  prep- 
aration of  this  translation.  The  quantitative  side  of 
organic  chemistry,  apart  from  elementary  analysis,  is 
almost  always  neglected  in  the  ordinary  courses  of  in- 
struction, and  when  the  need  for  it  arises,  in  the  pros- 
ecution of  research  work  for  instance,  it  is  difficult  to 
obtain  a  comprehensive  view  of  the  methods  which  are 
available  without  undue  expenditure  of  time.  This 
little  work  supplies,  for  the  first  time,  a  systematic 
treatment  of  these  methods  which,  it  is  hoped,  may 
help  to  remove  this  drawback  and  may  also  encour- 
age the  introduction  of  some  quantitative  work  into 
the  college  courses  of  organic  preparations,  since  such 
a  departure  could  scarcely  fail  to  be  beneficial  in 
various  ways  to  the  student.  From  the  translator's 
experience  with  the  German  edition  he  believes  that 
the  present  one  will  be  serviceable  to  instructors  and 
senior  students  of  organic  chemistry.  Considerable 
care  has  been  bestowed  on  the  proof-sheets,  and  it  is 
hoped  that  the  errors  which  may  have  escaped  notice 
are  not  too  glaring. 

LEWIS   INSTITUTE,  CHICAGO,  ILL., 
October  1899. 

viii 


CONTENTS. 


PAGE 

INTRODUCTORY.  .  i 


CHAPTER  I. 

i 
DETERMINATION  OF  HYDROXYL,  OH 4 

Determination  of  hydroxyl,  4.  Acylation,  4  Prep- 
aration of  acetyl  derivatives,  6.  (A)  By  acetyl  chlo- 
ride, 6.  (B)  By  acetyl  bromide,  8.  (C)  By  acetic  anhy- 
dride, 8.  (D)  By  glacial  acetic  acid,  10.  (E)  Bychlor- 
acetyl  chloride,  10.  Isolation  of  acetyl  derivatives,  10. 
Determination  of  the  acetyl  groups,  n.  (A)  Hydro- 
lytic  methods,  it.  (B)  Additive  method,  18.  (C) 
Potassium  acetate  method,  18.  (D)  Distillation 
method,  19.  Benzoyl  derivatives,  21.  (A)  Preparation 
from  benzoyl  chloride,  21.  (B)  Preparation  from 
benzoic  anhydride,  25.  (C)  Preparation  of  substituted 
benzoic  acid  derivatives  and  of  phenylsulphonic  chlo- 
ride, 26.  Acylation  by  means  of  substituted  benzoic 
acid  derivatives  and  of  phenylsulphonic  chloride,  27. 
Analysis  of  benzoyl  derivatives,  28.  Acylation  by 
means  of  other  acid  radicles,  30.  Alkylation  of  hy- 
droxyl groups,  31.  Preparation  of  benzyl  derivatives, 
32.  Esterification  of  phenols,  33.  Preparation  of 
carbamates  by  means  of  carbamyl  chloride,  33.  Prep- 
aration of  diphenylcarbamyl  chloride,  34.  Prepara- 
tion of  phenylcarbamic  acid  derivatives,  35.  Prepara- 

ix 


CONTENTS. 


tion  of  phenylisocyanate,  35.  Action  of  phenylisocya- 
nate  on  hydroxyl  derivatives,  35.  Action  of  organic 
magnesium  derivatives  on  hydroxyl  compounds,  37. 

CHAPTER  II. 

i  i 

DETERMINATION  OF  METHOXYL,  CH3O-,  ETHOXYL,  C2H5O-, 

AND  CARBOXYL,  CO.OH 38 

Determination  of  methoxyl,  S.  Zeisel's  method,  38 
For  non- volatile  substances,  42.  For  volatile  com- 
pounds, 45.  Modified  method,  46.  Method  for  the 
differentiation  of  methoxyl  and  ethoxyl,  47.  Deter- 
mination of  ethoxyl,  48.  Determination  of  carboxyl, 
48.  (A)  Analysis  of  metallic  salts,  49.  (B)  Titration 
of  acids,  50.  (C)  Etherification,  51.  (D)  Electrolytic 
conductivity  of  sodium  salts,  53.  (E)  Indirect  methods 
for  the  determination  of  the  basicity  of  acids,  58.  (i) 
Carbonate  method,  58.  (ii)  Ammonia  method,  59. 
(iii)  Hydrogen  sulphide  method,  60.  (a)  Volumetric 
method,  61.  (6)  Titration  method,  63.  (iv)  Iodine- 
oxygen  method,  64. 


CHAPTER  III. 

ii                              IT 
DETERMINATION  OF  CARBONYL,  CO,  METHYLENE,  CH2 68 

Preparation  of  phenylhydrazones,  68.  Preparation 
of  parabromophenylhydrazine,  72.  Substituted  hy- 
drazones,  73.  Indirect  method,  74.  Preparation  of 
oximes,  80.  Preparation  of  semicarbazones,  84,  87. 
Preparation  of  semicarbazine  salts,  84.  Preparation 
of  thiosemicarbazine  derivatives,  88.  Preparation  of 
semioxamazine,  90.  Preparation  of  amidoguanidine 
derivatives,  90.  Paramidodimethylaniline  derivatives, 
92.  Barium  salts  of  aromatic  aminocarboxylic  and 
aminosulphonic  acids,  93.  Other  derivatives  of  alde- 
hydes and  ketones,  93.  Determination  of  methylene, 
94- 


CONTENTS.  XI 


CHAPTER  IV. 

PAGE 

Determination  of  the  amino  group,  95.  Determina- 
tion of  aliphatic  amines,  (i)  nitrous  acid  method,  95. 
(ii)  Analysis  of  salts  and  double,  salts,  97.  £iii)  Acety- 
lation, 97.  (iv)  Titration  with  oenanthaldehyde,  97 
Determination  of  aromatic  amines,  97.  (i)  Titration  of 
the  salts,  98.  (ii)  Preparation  of  diazo-derivatives:  (a) 
conversion  into  an  azo  dye,  99.  (b)  Indirect  method, 
1 01.  (c)  Azoimide  method,  102.  (d)  Sandmeyer- 
Gattermann's  reaction,  103.  (iii)  Analysis  of  salts  and 
double  salts,  105.  (iv)  Acetylation,  106.  Alkylation, 
108.  Determination  of  the  nitrile  group,  108.  De- 
termination of  the  amido  group,  no.  Determination 
of  the  imine  group:  (i)  Acetylation,  112.  (ii)  Alkyla- 
tion, 113.  (iii)  Analysis  of  salts,  113.  (iv)  Elimina- 
tion of  imidogen  as  ammonia,  113.  Determination  of 
methyl  imine,  114.  (i)  Determination  with  one  alkyl 
linked  to  nitrogen,  114.  (ii)  Determination  with  two 
or  more  alkyls  linked  to  nitrogen,  116.  (iii)  Successive 
determination  of  alkyl  groups,  117.  (iv)  Determina- 
tion of  methyl  imine  in  presence  of  methoxyl,  117.  (v) 
General  remarks  on  the  method,  118.  Determination 
of  ethyl  inline,  119.  Differentiation  of  the  methyl 
imide  and  ethyl  imine  groups,  119. 


CHAPTER  V. 

Determination  of  the  diazo-group  (A)  Aliphatic 
diazo-compounds:  (i)  Titration  with  iodine,  120.  (ii) 
Analysis  of  the  iodine  derivative,  121.  (iii)  Determina- 
tion of  the  nitrogen  in  the  wet  way,  121.  (B)  Aromatic 
diazo-compounds.  Diazonium  derivatives,  123.  De- 
termination of  the  hydrazide  group,  125.  (i)  By 
oxidation,  125.  (ii)  lodometric  method,  127.  Deter- 
mination of  the  nitro-group.  (A)  Titration  method, 
129.  (i)  Method  for  non- volatile  compounds,  130.  (ii) 
Modifications  for  volatile  compounds,  131.  (B)  Diazo- 


Xii  CONTENTS. 

PAGS 

method,  132.  Determination  of  the  nitroso-group,  132. 
Determination  of  the  iodoso-  and  iodoxy-groups,  134. 
Determination  of  the  peroxide  group,  135.  The  iodine 
number,  106. 

APPENDIX. 

Additional  methods  for  the  determination  of  various 
groups,  142.  Table  of  the  weights  of  a  cubic  centimeter 
of  hydrogen,  194.  Tension  of  aqueous  vapor,  196, 

Table  for  the  value  of  —      — ,  196.     Index,  199. 


ABBREVIATIONS. 


THE  following  abbreviations  have  been  used  in  the 
bibliographical  references: 


Am.  Chem.  Journ. 

Ann. 

Ann.  de  Ch.  Ph. 

Arch.  Pharm. 

B. 

Bull. 
C. 

Ch.  R. 
Ch.  Ztg. 
Ch.  N. 
C.  r. 

Dingl. 
Gazz. 
H. 
J- 

J.  Am. 

Journ.  Chem.  Soc. 

J.pr. 

M. 

M.  &J. 


American  Chemical  Journal. 

Liebig's  Annalen  der  Chemie  und  Pharmacie. 

Annales  de  Chimie  et  de  Physique. 

Archiv  der  Pharmacie. 

Berichte  der  Deutschen  chemischen  Gesell- 

schaft. 

Bulletins  de  la  Societe  Chimique  de  Paris. 
Chemisches  Centralblatt. 
Chemische  Revue. 
Chemiker-Zeitung. 
Chemical  News. 
Comptes  rendus  de  1'Academie  des  sciences 

(Paris). 

Dingler's  polytechnisches  Journal. 
Gazzetta  chimica  italiana. 
Beilstein,  Handbuch. 
Jahresbericht     uber     die     fortschritte     der 

Chemie. 

Journal  of  the  American  Chemical  Society. 
Journal  of  the  Chemical  Society  of  London. 
Journal  fur  praktische  Chemie. 
Monatshefte  fur  Chemie. 
V.  Meyer  and  P.  Jacobson,  "Lehrbuch  der 

organischen  Chemie." 

xiii 


xiv  .  ABBREVIATIONS. 

Rec.  Recueil  des  travaux  chimiques  des   Pays- 

Bas. 
S.  Seelig,  "Organische    Reaktionen     und    Re- 

agentien." 
W.  Ann.  Wiedemann's    Annalen     der     Physik     und 

Chemie. 

Z.  Zeitschrift  fur  physikalische  Chemie. 

Z.  An.  Zeitschrift  fur  anorganische  Chemie. 

Z.  anal.  Zeitschrift  fur  analytische  Chemie. 

Z.  ang.  Ch.  Zeitschrift  fur  angewandte  Chemie. 

Z.  f.  Ch.  Zeitschrift  fur  Chemie. 

Z.  physiol.  Ch.  Zeitschrift  iiir  physiologische  Chemie. 

Z.  Rub.  Zeitschrift  des   Vereines  fur  Riibenzucker- 

industrie. 


DETERMINATION  OF  RADICLES  IN 
CARBON  COMPOUNDS. 


INTRODUCTION. 

THE  quantitative  analysis  of  inorganic  compounds, 
as  usually  performed,  consists  almost  exclusively  in 
the  determination  of  ions,  as  this  generally  suffices  for 
the  identification  of  the  substance;  but  to  attain  the 
same  end  in  the  case  of  organic  bodies  the  elementary 
analysis  requires  supplementing  by  other  methods. 
The  percentage  composition  gives  no  information  about 
the  relative  arrangement  of  the  atoms  in  the  molecule, 
but  the  demand  for  methods  of  analysis  which  will 
yield  such  knowledge  increases  with  our  growing  in- 
sight into  the  constitution  of  carbon  compounds.  To 
supply  this  want  certain  "  quantitative  reactions  "  have 
been  applied  for  the  determination  of  special  groups  of 
atoms;  they  are  widely,  but  almost  exclusively,  em- 
ployed by  technologists  in  the  analysis  of  such  sub- 
stances as  fats,  waxes,  resins,  ethereal  oils,  caoutchouc, 
glue,  paper,  etc.,  and  the  results  are  known  as  the 
•'acid  number,"  "  saponification  number,"  "  iodine 
number,"  "methoxyl  number,"  "acetyl  number," 
"  carbonyl  number,"  etc.  The  determination  of  such 


2  RADICLES    IN    CARBON   COMPOUNDS. 

"  numbers"  or  ''values"  obtained  by  the  action  of 
some  reagent  on  a  known  weight  of  substance  is  fre- 
quently insufficient  for  scientific  investigation  ;  this  ren- 
ders it  necessary  to  work  out  a  special  process  for  each 
group  of  organic  compounds  in  order  to  determine  the 
radicles  which  are  present. 

The  reactions  of  organic  compounds  are  only  in  part 
ionic;  usually  they  are  conditioned  by  the  configura- 
tion and  state  of  equilibrium  of  the  molecule,  and  con- 
sequently a  reaction  which  readily  occurs  with  one 
compound  may  totally  fail  with  another  of  very  similar 
constitution,  on  account  of  stereoisomerism ;  or,  by 
substitution,  one  radicle  may  approximate  more  or 
less  closely  to  the  character  and  functions  of  another. 
In  these  cases  the  quantitative  separation  of  the  com- 
pounds is  more  difficult,  and  can  frequently  be  accom- 
plished only  by  differences  in  crystallizing  power,  or 
by  the  preparation  of  derivatives  which  can  be  volatil- 
ized without  decomposition. 

Since  the  course  of  a  particular  reaction  of  an  inor- 
ganic compound  is  only  conditioned  by  the  behavior 
of  the  ions  which  are  to  be  determined,  it  follows  that 
the  analytical  methods  are  in  a  sense  independent  of 
the  nature  of  the  compounds  investigated,  and  conse- 
quently of  very  wide  application.  The  matter  is  far 
otherwise  with  organic  compounds:  there  are  very  few 
processes  which,  like  Ziesel's  method  for  determining 
methoxyl,  can  be  applied  almost  universally.  Usually, 
then,  it  becomes  necessary  for  the  analyst  himself  to 
select  the  method  most  appropriate  for  his  special  pur- 
pose, or,  perhaps  by  a  combination  of  several,  to  de- 
vise one  which  may  lead  to  the  desired  result.  The 


INTRODUCTION.  3 

successful  methods  hitherto  proposed  for  the  determina- 
tion of  organic  radicles  have  been  collected  together  in 
this  work,  and  it  is  hoped  that  they  may  serve  to  indi- 
cate the  direction  in  which  research  may  be  success- 
fully prosecuted  for  the  discovery  of  new  ones  applicable 
to  novel  conditions  which  may  arise. 


CHAPTER  I. 

DETERMINATION  OF  HYDROXYL  (-OH). 

THE  determination  of  the  hydroxyl  radicle  in  organic 
compounds  depends  on  the  preparation  of  derivatives  by 
the  following  methods: 

(I.)  ACYLATION. — This  consists  in  the  introduction 
into  the  hydroxyl  compound  of  the  radicle  of  one  of 
the  acids  mentioned  below: 

Acetic  acid ; 

Benzoic  acid  and  its  substitution  products; 

Plicnylsulplionic  acid. 
Of  less  frequent  employment  are  the  radicles  of 

Propionic  acid; 

Isobutyric  acid; 

Phenylacetic  acid. 

(II.)  ALKYLATION. — Confined  usually  to  the  prep- 
aration of  benzyl  derivatives. 

(III.)  The  preparation  of  CARBAMATES. 

(IV.)  The  formation  of  ESTERS  OF  PHENYLCARBAMIC 
ACID. 

As  a  rule,  attention  is  first  directed  to  the  prepara- 
tion of  an  acetyl  or  benzoyl  derivative,  the  former 
usually  byLiebermann  and  Hermann's  method  (see  page 
8),  the  latter  by  that  of  Lossen  or  Schotten-Baumann 
(see  page  22).  Not  infrequently,  however,  it  becomes 

4 


DETERMINATION   OF   HYDROXYL.  5 

necessary  to  resort  to  one  of  the  other  forms  of  pro- 
cedure in  order  to  determine  the  constitution  of  the 
body  under  investigation.  As  the  groups  NH,  NH2 
and  SH  are  all  capable  of  acylation,  care  is  required  to 
avoid  confusion, if  the  original  compound  cpntains  nitro- 
gen or  sulphur.  Instances  are  known  of  acetylation 
taking  place  in  the  absence  of  hydroxyl  and  of  the 
groups  just  referred  to,  thus  diacetylhydroquinol  is 
formed  from  quinone,  acetic  anhydride,  and  sodium 
acetate;1  tetrachloroquinone  and  acetyl  chloride  yield 
diacetyltetrachlorohydroquinol.2  Acetylating  reagents 
frequently  cause  isomerization  or  polymerization,  and 
sometimes  lead  to  the  production  of  anhydrides,  etc.  ; 
thus  benzhydrylacetocarboxylic  anhydride  is  obtained 
from  the  isomeric  orthocinnamocarboxylic  acid  by  the 
action  of  acetic  anhydride  and  sodium  acetate,3  and 
isocantharidin  is  produced  from  cantharic  acid  when 
heated  in  a  sealed  tube  with  acetyl  chloride.4  In  view 
of  these  and  similar  facts,  care  should  be  taken  to 
hydrolyse  the  presumptive  acetyl  derivative  and  identify 
the  product  with  the  original  substance;  should  this 
not  be  possible,  then  proof  must  be  obtained  that  the 
derivative  does  actually  contain  the  acid  radicle,  the 
introduction  of  which  has  been  attempted. 

1  Sarauw,  B.  12,  680. 

2  Graebe,  Ann.  146,  13. 

3  Benedikt  and  Ehrlich,  M.  9,  529. 

4  Anderlini   and  Ghiro,  B.  24,  1998.     Cf.  Pinner  B.  27  (1894),  2861; 
28(1895),  456. 


6  RADICLES    IN    CARBON    COMPOUNDS. 

METHODS  OF  ACETYLATION. 

(l)    PREPARATION  OF  ACETYL  DERIVATIVES. 

The  following-  reagents  are  employed  for  the  prepara- 
tion of  acetyl  derivatives  from  organic  compounds  con- 
taining hydroxyl  groups: 

(A)  Acetyl  chloride; 

(B)  Acetyl  bromide; 

(C)  Acetic  anhydride,  sodium  acetate; 

(D)  Glacial  acetic  acid; 

(E)  CJiloracetyl  chloride. 

(A)  Acetylation   by  Means   of  Acetyl   Chloride. 

(a]  Many  hydroxyl  derivatives  react  with  acetyl 
chloride  when  simply  mixed  or  digested  on  the  water- 
bath.  It  is  convenient  to  dissolve  the  substance  and 
the  chloride  in  benzene,  and  boil  the  solution  until  the 
evolution  of  hydrochloric  acid  ceases.  If  there  is  no 
danger  of  the  hydrogen  chloride  causing  secondary 
reactions  (hydrolysis),  of  which  an  interesting  case  has 
been  recorded,1  the  substance  may  be  heated  with  the 
chloride  in  a  sealed  tube  without  solvent.  Certain 
dibasic  hydroxy  acids  of  the  aliphatic  series,  such  as 
mucic  acid,  which  are  not  changed  with  acetyl  chloride 
alone,  frequently  react  with  it  on  the  addition  of  zinc 
chloride.2  In  general,  it  may  be  stated  that  acetyl 
chloride  only  reacts  readily  with  alcohols  and  phenols, 
but,  as  it  may  lead  to  the  production  of  anhydrides 

1  Herzig  and  Schiff,  B.  30,   378.     Cf.  Bamberger  and  Landsiedl,  M. 
jg,  307.     Brauchbar  and  Kohn,  Ibid.  19,  27,  foot-note. 

2  S.f  p.  258. 


is  nil  v  c.rt«7i 

OF 


DETERMINATION    OF    HYDROXYL.  / 

from  polybasic  acids,  these  are  usually  employed  in 
the  form  of  esters,  the  use  of  which  has  the  additional 
advantage  of  yielding  products  that  are  much  more 
easily  distilled  than  the  corresponding  derivatives  of 
the  acids  themselves.1 

(b)  The  following  method  2  is  frequently  more  con- 
venient than  the  "  acid  "  acetylation  just  described. 
The  substance  is  dissolved  in  ether  or  benzene,  and 
digested  with  the  necessary  quantity  of  acetyl  chloride 
and  dry  alkali  carbonate,  the  latter  being  in  the  pro- 
portion necessary  to  form  a  hydrogen  salt  as  repre- 
sented by  the  equation  : 


CH3.COC1+K2C03->R.O.CO.CH 


KC1  +  KHCO3. 


(c)  Acetylation     by   means   of  acetyl   chloride   and 
aqueous  alkali  is  described  on  p.  24. 

(d)  It  is  often  convenient  to  allow  the  acetyl  chloride 
to   react   with   the    compound    under   investigation   in 
pyridine  solution.3 

(e)  Diacetylacetone    could    only    be    acetylated    by 
allowing  its  barium  salt  to   react  with  acetyl  chloride 
at  the  ordinary  temperature.4 

(/)  Instead  of  acetyl  chloride,  phosphorus  trichloride, 
or  preferably  the  oxychloride,  or  phosgene  may  be 
employed  ;  they  are  allowed  to  react  on  a  mixture  of 
the  substance  and  acetic  acid  in  the  proper  propor- 

1  Wislicenus,  Ann.  129,  17. 

2  L.  Claisen,  B.  27,  3182. 

3  A.  Deninger,  B.  28,  1322.     Cf.  A.  Einhorn  and  F.  Holland!,  Ann. 
301  (1898),  95. 

*  Feist,  Ibid.  28,  1824. 


RADICLES    IN   CARBON    COMPOUNDS. 

tions.1  Thus,  for  example,  phenol  is  readily  acetylated 
by  heating  it  at  80°  with  an  equimolecular  proportion 
of  acetic  acid  and  adding  phosphorus  oxychloride 
(J  molecule)  gradually,  by  means  of  a  dropping  funnel. 
When  hydrogen  chloride  is  no  longer  evolved  the 
product  is  poured  into  cold  aqueous  soda  solution ;  after 
further  washing  with  highly  dilute  alkali  it  is  treated 
once  with  water,  dried  by  means  of  calcium  chloride, 
and  distilled. 

(B)  Acetylation  by  Means  of  Acetyl  Bromide. 

Acetyl  bromide  has  been  used  2  for  the  acetylation 
of  certain  sugars ;  the  products  are  aceto  bromides  and 
usually  crystallize  well. 

(C)  Acetylation  by  Means  of  Acetic  Anhydride. 

(a)  The  substance  is  generally  boiled  with  5—10  parts 
of  anhydride,  or  heated  with  it  in  a  sealed  tube  for 
several  hours.  The  higher  fatty  acids  yield  anhydrides 
by  this  treatment.3 

(b~)  Not  infrequently  the  substances  must  be  allowed 
to  react  during  a  short  time  only,  at  a  comparatively 
low  temperature.  Bebirine,  for  instance,  is  readily 
acetylated  when  digested  with  the  anhydride  during  a 
short  time  at  4O°-5O°,  but  by  its  prolonged  action 
amorphous  substances  are  formed.4 

(c)  The  substance  may  be  mixed  with  an  equal 
weight  of  dry  sodium  acetate,  and  3-4  parts  of  the 

1  J-  Pr-  25,  282;  26.  62;  31,  467. 

2  W.   Koenigs  and  E.  Knorr,  B.  34  (1901),  957;  E.  Fischer  and  E.  F. 
Armstrong,  Ibid.  2885. 

3  A.  Albitzky,  Journ.  Chem.  Soc.  (1899)!,  862.     J.  Russ.  Chem.  Soc., 
31  (1899),  103.  4  B.  29,  2057. 


DETERMINATION   OF   HYDROXYL.  9 

anhydride,  and  boiled  for  a  short  time  in  a  reflux  ap- 
paratus ; 1  in  the  case  of  small  quantities  of  substance 
2-3  minutes'  boiling  may  suffice.  The  action  appears 
to  depend  on  the  production  of  a  sodium  salt  of  the 
compound  under  examination,  which  then  reacts  with 
the  anhydride.  This  method  yields,  on  the  whole, 
the  most  trustworthy  results  of  any,  and  seldom  fails 
to  give  completely  acetylated  derivatives.  It  fails  in 
the  case  of  the  o'-hydroxyl  of  the  hydroxyquinolines,2 
though  these  compounds  yield  benzoyl  derivatives. 
Occasionally  the  presence  of  sodium  acetate  is  harmful.3 

(d)  A  mixture  of  acetic  anhydride  and  acetyl  chlo- 
ride may  be  used,  or  the  action  of  the  anhydride  may 
be  started  by  means  of  a  drop  of  concentrated  sulphuric 
acid,4  which  frequently  causes  a  vigorous  reaction  at 
the  ordinary  temperature  when  otherwise  a  high  tem- 
perature and    pressure  would    have  to    be   employed. 
The  method  is  applicable  to  many  aldehydes,  hydroxy- 
aldehydes,     phenols,    substituted     phenols    containing 
negative    groups,     and    polyhydric    alcohols,    also    to 
aminophenols  and  amines  containing  one  or  more  nega- 
tive groups.      It  is  less  satisfactory  with  the  ethers  of 
phenols,  and  with  hydrocarbons  of  the  series   CWH2W_6.5 

(e)  The    addition    of   zinc    chloride6  and  of  stannic 
chloride7  has  also  been  recommended. 

1  C.  Licbermann  and  O.  Hermann,  B.  n,  1619. 

2  J.  Diamant,  M.  16,  770.     Cf.  La  Coste  and  Valeur,  B.  20,  1822. 

3  Herzig,  M.  18,  709. 

4  Franchimont,  B.  12,  1941.     Cf.  Thiele,  B.  31,  1249. 

5  G.  Freyss,  Journ.  Chem.  Soc.,  76  (1899),  i.  874. 

6  Franchimont,  C.  r.  89,  711;  B.  12,  2058.     Cf.  Maquenne,  Bull.  48, 

54,  7i9- 

7  H.  A.  Michael,  B.  27,  2686. 


IO  RADICLES    IN   CARBON   COMPOUNDS. 

(/)  Acetic  anhydride  in  aqueous  solution  has  also 
been  successfully  employed  (cf.  p.  7). 

(D)  Acetylation  by  Means  of  Glacial  Acetic  Acid. 

Acetylation,  especially  that  of  alcoholic  hydroxyl 
groups,  may  often  be  accomplished  by  heating  the 
substance  with  glacial  acetic  acid,  under  pressure  if 
necessary;  the  addition  of  sodium  acetate  is  also  ad- 
vantageous, and,  in  some  cases,  this  is  the  only  method 
which  gives  the  desired  result.  Thus,  camphorpinacone 
yields  a  chloride  when  treated  with  acetyl  chloride, 
and  is  not  changed  by  boiling  acetic  anhydride,  but 
when  it  is  boiled  with  glacial  acetic  acid  for  a  short 
time,  a  stable  acetyl  derivative  is  formed,  and  an 
isomeric  labile  one  by  the  action  of  the  acid  at  the 
ordinary  temperature  during  twenty-four  hours.1 

(E)  Acetylation  by  Means  of  Chloracetyl  Chloride. 
This  reagent  has  also  bee'n  employed  occasionally.2 
A  collection  has  been  made  of  references  in  the  lit- 
erature to  hydroxyl  derivatives  which  are  not  capable 
of  acetylation.3    Vide  also  p.  143. 

ISOLATION  OF  THE  ACETYL 
DERIVATIVES. 

Acetyl  derivatives  are  isolated  by  pouring  the  pro- 
duct of  the  reaction  into  water.  The  excess  of  acetic 
acid  may  also  be  removed  by  the  addition  of  methylic 
alcohol  to  convert  it  into  methylic  acetate,  which  is 

1  Beckmann,  Ann.  292,  17. 

2  Klobukowsky,  B.  10,  881.     Cf.  Ibid.  31,  2790;  20,  2330. 

3  M.   IQ,   22. 


DETERMINATION  OF  HYDROXYL.        II 

then  volatilized;  residual  acetic  anhydride  is  separated 
by  distillation  under  reduced  pressure.  Acetyl  deriva- 
tives, soluble  in  water,  may  often  be  precipitated  by 
the  addition  of  solid  sodium  carbonate,  or  by  extract- 
ing the  solution  with  chloroform  or  benzene.  Ethylic 
acetate  frequently  proves  to  be  an  excellent  medium 
for  the  subsequent  recrystallization  of  the  acetyl  product. 
Vide  also  p.  1 44. 

DETERMINATION  OF  THE  ACETYL 
GROUPS. 

The  various  acetyl  derivatives  of  a  compound  usually 
differ  little  in  percentage  composition,  so  that  ele- 
mentary analysis  seldom  affords  information  as  to  the 
number  of  acetyl  groups  which  have  entered  the  orig- 
inal molecule;  thus,  the  mono-,  di-,  and  tri-acetyl  de- 
rivatives of  the  trihydroxybenzenes  have  an  identical 
percentage  composition.  In  such  cases  the  acetyl 
groups  must  be  eliminated,  and  the  acetic  acid  formed 
determined  directly  or  indirectly. 

(A)  Hydrolytic  Methods. 

The     following    reagents    are    employed    for    the 
hydrolysis  of  acetyl  compounds : 
(a)    Water; 

(&)  Potassium  hydroxide,  sodium  hydroxide; 
(c)  Barium  hydroxide; 
(a]  Ammonia; 
(e)   Chalk; 
(/)  Magnesia; 
(g]  Hydrochloric  acid; 
(/2)  Sulphuric  acid; 
(z)  Hydriodic  acid. 


12  RADICLES    IN    CARBON    COMPOUNDS. 

(a)  Some  acetyl  derivatives  are  hydrolysed  by  heat- 
ing with  water  under  pressure;   thus  butenyltriacetin, 
C4H7  (C2H3O2)3,  is  completely  hydrolysed  by  heating 
it  with  forty  parts  of  water  at   160°  in  a  sealed  tube, 
and     the     liberated     acetic     acid     may    be     titrated.1 
Diacetylmorphine  also  loses  one  acetyl  group  by  boil- 
ing it  with  water,2  and  acetyl  dihydroxypyridine  is  still 
more  unstable.3 

(b)  Hydrolysis  by  means  of  potassium  hydroxide  or 
sodium  hydroxide  is  especially  useful  for  the  analysis 
of  fats.      The  compound  (1-2  grams)   is  gently  boiled 
on  the  water-bath  for  fifteen  minutes,  in  a  wide-necked 
flask   of   100-150  cc.    capacity,   with  alcoholic  potash 
(25-50  cc.)  of  known  strength,  which  should  be  about 
N/2.      During  the    heating   the   neck  of  the  flask    is 
covered  with  a  cold  funnel;   at  the  conclusion  of  the 
hydrolysis    phenolphthalein  is  added,   and  the  excess 
of  alkali  determined  by  means  of   N/2    hydrochloric 
acid.4     In  some  cases  it  is  necessary  to  distill  off  the 
acetic  acid    before    titration  on  account    of   the    pro- 
duction of   anhydrides   of   the  higher    fatty    acids    by 
the  action  on  them  of  acetic  anhydride.5     The  method 
may  also  be   employed   for   the   determination   of  the 
molecular  weight    of  the  aliphatic    alcohols.      This  is 

obtained  from  the  expression  M  =  — == —     -  42,  where 

1  Lieben  and  Zeisel,  M.  i,  835. 

2  Wright- Becket,  Journ.  Ch.  Soc.,  12,  1033.   Danckwortt,  Arch.  Pharm. 
226,  57- 

3  M.  18,  619. 

4  Benedikt  and  Ulzer,  M.  8,  41. 

5  A.  Albitzky,  Journ.  Chem.    Soc.   76  (1899),  i.  862.     J.  Russ.  Chem. 
Soc.  (1899),  31,  103. 


DETERMINATION  OF  HYDROXYL.        13 

M  is  the  molecular  weight,  and  V  the  number  of  milli- 
grams of  potassium  hydroxide  required  to  hydrolyse  I 
gram  of  the  acetyl  derivative.  If  the.  compound  is 
affected  by  air,  the  hydrolysis  is  carried  out  in  an  at- 
mosphere of  hydrogen ; :  should  the  original  compound 
be  insoluble  in  dilute  hydrochloric  acid,  the  acetyl  de- 
rivative may  be  boiled  with  aqueous  potash,  the  pro- 
duct acidified,  and  the  precipitate  weighed.2 

N 

Methyl  alcoholic  sodium  hydroxide  —  has  been  suc- 
cessfully employed 3  for  the  hydrolysis  of  octacetyl- 
sucrose.  The  mixture  is  allowed  to  remain  at  the 
ordinary  temperature  over  night,  and  then  titrated  with 

N 

—  sulphuric  acid,  with  phenolphthale'in  as  indicator. 

(c)  Barium  hydroxide  may  be  employed  in  many 
cases  where  potash  causes  decomposition,  thus 
haematoxylin  yields  formic  acid  when  boiled  with 
highly  dilute  alkali,  but  barium  hydroxide  readily 
hydrolyses  its  acetyl  derivatives  without  further  de- 
composition.4 One  method  of  procedure  5  is  to  boil  the 
compound  under  investigation  with  the  hydroxide  dur- 
ing 5-6  hours  in  a  reflux  apparatus.  The  product  is 
filtered,  the  filtrate  treated  with  carbonic  anhydride  in 
excess,  again  filtered,  and  the  filtrate  evaporated. 
The  residue  is  dissolved  in  water,  the  liquid  filtered 


1  Klobukowsky,  B.  10,  882. 

2  Vortmann,  "  Anleitung  zur  chemischen  Analyse  organischer  Stoffe," 

P-  59- 

3  W.  Konigs  and  E.  Knorr.  B.  34  (1901),  4348. 

4  Erdmann  and  Schultz.  Ann.  216,  234. 
*  Herzig,  M.  5,  86. 


14  RADICLES    IN    CARBON   COMPOUNDS. 

and,  after  being  washed,  the  barium  in  the  filtrate  is 
determined  as  sulphate.  Since  all  the  above  opera- 
tions are  conducted  in  glass  vessels  and  some  alkali 
from  these  may  neutralize  a  portion  of  the  acetic  acid, 
a  correction  becomes  necessary.  This  is  obtained  by 
concentrating  the  filtrate  from  the  barium  sulphate  in  a 
platinum  dish ;  when  the  excess  of  sulphuric  acid  has 
been  volatilized,  the  residue  is  treated  with  pure  am- 
monium carbonate  until  its  weight  becomes  constant. 
It  is  now  dissolved  in  water,  the  silica  removed,  and 
the  sulphates  in  the  filtrate  determined  as  barium  sul- 
phate, the  weight  of  which  is  added  to  that  first  found. 
If  the  hydrolysis,  etc.,  can  be  carried  out  in  vessels  of 
silver,1  the  above  correction  is  unnecessary.  The 
action  of  the  barium  hydroxide  solution  is  promoted 
by  the  previous  addition  to  the  substance  of  a  few 
drops  of  alcohol.2 

(d)  Aqueous  ammonia  readily  hydrolyses  the  dia- 
cetyl  derivative  of  benzoin  yellow,   alkalis  cause    de- 
composition.3 

(e)  Chalk  in  aqueous  suspension  readily  eliminates 
bromine  and  the  acetyl  group  from  acetyloxyacetophe- 
none  bromide.4 

(/)  Magnesia  is  generally  employed  in  the  following 
manner:5  Ordinary  "ignited  magnesia,"  and  the 
basic  carbonate  (magnesia  alba)  are  both  unsuitable, 
as  they  contain  alkali  carbonates  which  are  difficult  to 

1  Lieben  and  Zeisel,  M.  4,  42  ;  7,  69. 

2  Earth  and  Goldschmiedt,  B.  12,  1237. 

3  C.  Graebe,  B.  31,  2976. 

4  P.  Friedlander  and  J.  Neudorfer,  Ibid.  30,  Io8l.     Cf.  M.  19,  42. 

5  II.  Sckiff,  Ibid.  12,  1531.     Ann.  154,  n. 


DETERMINATION    OF    HYDROXYL.  I  5 

remove.  The  magnesia  is  prepared  from  the  sulphate 
or  chloride,  which  must  be  free  from  iron ;  the  solu- 
tion is  treated  with  alkali  hydroxide  in  quantity  insuffi- 
cient to  cause  complete  precipitation ;  after  thorough 
washing  the  magnesia  is  retained  as  a  paste  under 
water.  The  acetyl  derivative  (1  —  1.5  grams)  is  inti- 
mately mixed  with  the  magnesia  paste  (about  5  grams) 
and  a  little  water,  and  transferred,  together  with  water 
(100  cc.),  to  a  flask  of  resistant  glass.  The  mixture  is 
boiled  in  a  reflux  apparatus  during  4-6  hours,  although 
usually  the  hydrolysis  is  completed  in  2-3  hours.  The 
liquid  is  concentrated  in  the  flask  to  a  third  of  its  orig- 
inal volume,  cooled,  filtered  by  means  of  a  pump,  the 
insoluble  portion  washed,  and  the  filtrate  and  wash- 
ings treated  with  ammonium  chloride,  ammonium 
hydroxide,  and  amrnoniacal  sodium  phosphate.  The 
magnesium  ammonium  phosphate,  after  standing  during 
twelve  hours,  is  filtered,  dissolved  in  dilute  hydrochlo- 
ric acid,  and  reprecipitated  by  means  of  ammonium 
hydrate ;  I  part  of  Mg2P2O7  =  o.  774648  parts  of  C2H3O. 
The  solubility  of  magnesia  in  highly  dilute  solutions  of 
magnesium  acetate  is  too  small  to  require  a  correction. 
Even  "insoluble"  acetyl  derivatives  may  be  hydro- 
lysed  by  magnesia,  provided  that  they  are  in  a  finely 
divided  state,  the  boiling  being  prolonged  to  twelve 
hours  if  necessary.  The  magnesia  method  is  advan- 
tageous in  cases  where  the  use  of  alkali  causes  decom- 

o 

position  and  the  production  of  colored  substances 
which  render  titration  uncertain. 

(g)  If  hydrochloric  acid  (sulphuric  acid)  is  without 
action  on  the  hydroxyl  compound,  the  acetyl  deriva- 
tive is  heated  with  a  known  quantity  of  N/i  acid  in  a 


l6  RADICLES    IN    CARBON    COMPOUNDS. 

sealed  tube  or  pressure-flask  at  I2O°-I5O°,  and  the  lib- 
erated acetic  acid  titrated.1 

(ft)  Hydrolysis  by  means  of  sulphuric  acid  is  es- 
pecially advantageous  when  the  original  substance  is 
insoluble  in  it.  The  acid  employed  should  be  free 
from  oxides  of  nitrogen  and  contain  75  parts  of  con- 
centrated acid  in  32  parts  of  water.  The  dilute  acid 
(10  cc. )  is  mixed  in  a  flask  with  a  weighed  quantity  of 
the  acetyl  derivative  (about  I  gram),  which,  if  neces- 
sary, may  be  previously  moistened  with  three  or  four 
drops  of  alcohol ;  the  mixture  is  warmed  on  a  hot,  but 
not  boiling,  water-bath  for  a  half  hour,  diluted  with 
eight  volumes  of  water,  then  boiled  during  3-4  hours 
on  the  water-bath,  and  allowed  to  remain  during 
twenty-four  hours  at  the  ordinary  temperature.  The 
precipitated  hydroxyl  derivative  is  then  collected  on  a 
filter. 2-3-  Should  the  hydroxyl  derivative  not  be  com- 
pletely insoluble  in  the  dilute  acid  a  blank  experiment 
must  be  made  and  the  correction  introduced.3 

(Y)  The  following  process  4  is  stated  to  be  universally 
applicable.  The  acetyl  derivative  (0.2-0.4  gram)  is 
placed  in  the  flask  A,  Fig.  I,  together  with  dilute  (2 
acid:  I  water)  sulphuric  acid  (3  cc.);  after  some  time 
water  (3  cc.)  is  added.  The  mixture  is  heated  at 
6o°-7O°  until  complete  hydrolysis  is  effected.  Meta- 
phosphoric  acid  solution  (20  cc.)  containing  100  grams 


1  Schutzenberger,    Ann.    de    Ch.  Ph.    84,    74.     Ilerzfeld.  B.  13,  266. 
Schmoeger,  Ibid.  25,  1453. 

2  Liebermann,  B.  17,  1682.     Herzig,  M.  6,  867-890. 

3  Ciamician  and  Silber,  B.  28,  *395- 

4  F.  Wenzel,    M.  18  (1897),   659;   19,    22.     Journ.   Chem.  Soc.  74,  i. 
(1898),  234. 


DETERMINATION    OF    HYDROXYL.  I/ 

acid  and  450  grams  cryst.  disodium  phosphate  in  I  liter 
of  water  is  added,  the  flask  A  connected  with  the 
hydrogen  generating  apparatus  and  distilled  to  dryness 
under  greatly  reduced  pressure.  Water  (20  cc.)  is 


1  I 

FIG.   i. 

added  and  the  distillation  repeated.  The  apparatus  is 
now  filled  with  hydrogen,  the  pump-flask  B,  which  con- 

N 
tains  —  potassium  hydroxide,   and  its  condenser  are 

disconnected  and  the  excess  of  alkali  determined  by 
titration.  During  the  distillation  the  flask  C  is  heated 
in  water  to  the  temperature  of  A;  it  serves  to  retain 
traces  of  phosphoric  acid.  The  distillate  must  be  free 

N 
from  sulphurous  acid  when  titrated  against  —  iodine ;  if 


1 8  RADICLES    IN    CARBON   COMPOUNDS. 

this  is  not  the  case  the  sulphuric  acid  used  for  hy- 
drolysis must  be  diluted.  Halogen  and  sulphur  com- 
pounds must  be  mixed,  before  hydrolysis,  with  silver 
sulphate  and  cadmium  sulphate  respectively. 

(/)  Hydriodic  acid  has  also  been  employed  for  the 
hydrolysis  of  acetyl  derivatives.1 

Unhydrolysable  acetyl  compounds  derived  from 
orthoaminobenzaldehyde  have  been  described.2 

(B)  Additive  Method.3 

This  may  be  regarded  as  complementary  to  the 
method  described  under/.  In  cases  where  the  acetyl 
derivative  is  insoluble  in  cold  water,  and  the  acetyla- 
tion  proceeds  quantitatively,  the  yield  of  product  from 
a  given  weight  of  hydroxyl  compound  gives  a  meas- 
ure of  the  number  of  acetyl  groups  introduced.  The 
method  has  recently  been  applied  to  the  investigation 
of  the  acetylation  products  of  tannic  acid.4 

(C)  Weighing  the  Potassium  Acetate.5 

This  method  is  applicable  to  compounds  yielding 
potassium  salts  insoluble  in  absolute  alcohol.  The 
acetyl  derivative  (i—  2  grams)  is  boiled  with  a  slight 
excess  of  potassium  hydroxide  solution  until  it  is  com- 
pletely hydrolysed,  water  being  added  to  replace  that 
evaporated.  The  remaining  alkali  is  neutralized  with 
carbonic  anhydride,  the  liquid  evaporated  as  completely 

1  Ciamician,  B.  27,  421,  1630. 

2  R.  Pschorr,  Ibid.  31  (1898),  1289. 

3  Goldschmiedt  and  Hemmelmayr,  M.  15,  321. 
«  H.  Schiff,  Ch.  Ztg.  20,  865. 

6  Wislicenus,  Ann.  129,  181. 


DETERMINATION  OF  HYDROXYL.        19 

as  possible  on  the  water-bath,  and  the  residue  thor- 
oughly extracted  with  absolute  alcohol.  The  alcoholic 
solution  is  evaporated  to  dryness  and  the  residue  again 
extracted,  any  insoluble  matter  being  removed  and 
well  washed,  and  the  liquid  evaporated  in  a  tared  ves- 
sel. The  dried  potassium  acetate  remaining  is  then 
cautiously  fused,  allowed  to  cool  over  sulphuric  acid, 
and  weighed. 

(D)  Distillation  Method. 

Fresenius1  first  suggested  that  the  acetic  acid  from 
acetates  could  be  liberated  with  phosophoric  acid  and 
determined  by  distillation,  with  or  without  the  help  of 
steam.  The  method  was  then  applied  by  various 
chemists  to  the  hydrolysis  of  acetyl  derivatives,  but 
since  they  replaced  the  phosphoric  acid  by  sulphuric 
acid  their  results  were  not  satisfactory.2  Subsequently 
the  use  of  phosphoric  acid  was  again  proposed8.  The 
acetyl  product  is  hydrolysed  by  means  of  alkalis  or 
barium  hydroxide,  acidified  at  the  ordinary  tempera- 
ture with  phosphoric  acid,  filtered,  and  well  washed; 
the  filtrate  and  washings  are  then  distilled  until  the 
distillate  is  completely  free  from  acid,  fresh  water  being 
introduced  into  the  retort  from  time  to  time  as  may 
be  necessary.  The  distillation  is  at  first  carried  out 
over  a  flame  and  subsequently  from  an  oil-bath,  the 
temperature  being  allowed  to  rise  to  I4O°-I5O°,  or  a 
water-bath  may  be  employed,  in  which  case  the  pres- 

iZ.  anal.  Ch.  5,  315;  14,  172. 

2  Erdmann  and  Schultz,   Ann.  216,  232.      Buchka  and  Erk,   B.  18, 
1142.     Schall,  Ibid.  22,  1561. 

3  Herzig,  M.  5,  90. 


20  RADICLES   IN    CARBON   COMPOUNDS. 

sure  is  reduced.1  The  connections  must  all  be  of 
caoutchouc,  as  corks  would  absorb  acetic  acid,  and  the 
alkali  and  acid  employed  must  be  free  from  nitrates  or 
nitrites.  The  presence  of  chlorides  is  not  hurtful,  as 
these  do  not  liberate  hydrogen  chloride  in  the  presence 
of  the  phosphoric  acid,  which  is  one  advantage  it  pos- 
sesses over  sulphuric  acid.2  The  distillate  is  treated 
with  baryta  water  in  excess,  and  concentrated  in  a 
platinum  dish,  the  excess  of  barium  removed  by  means 
of  carbonic  anhydride,  and  the  filtrate  evaporated  to 
dryness;  water  is  then  added,  the  liquid  filtered,  the 
insoluble  portion  well  washed,  and  the  barium  in  the 
filtrate  and  washings  determined  as  sulphate;  I  gram 
BaSO4  =  o.  5064  gram  C2H3O2  or  o.  5070  gram  C2H4O2. 
The  acetyl  groups  in  acetylated  gallic  acids3  were 
determined  by  mixing  the  substance  (3-4  grams)  with 
pure  alcohol  (5  cc.)  and  sodium  hydroxide  (2-3  grams) 
dissolved  in  water  (15  cc.).  After  the  hydrolysis  was 
completed,  the  alcohol  was  dissipated,  the  residue  acidi- 
fied with  phosphoric  acid,  the  acetic  acid  driven  over 
in  a  current  of  steam,  and  its  amount  determined  by 
titrating  the  distillate  with  sodium  hydroxide  solution, 
phenolphthalein  being  used  as  indicator.  One  source 
of  error  in  this  method  arises  from  carbonic  anhydride, 
which  is  always  present  in  the  sodium  hydroxide,  and 
is  often  produced  by  the  hydrolysis  itself;  it  volatil- 
izes together  with  the  acetic  acid.  The  difficulty 
may  be  avoided  by  heating  the  neutralized  liquid  to 
boiling,  adding  a  very  small  quantity  of  N/i  acid, 

1  II.  A.  Michael,  B.  27,  2686. 

2  R.  and  H.  Meyer,  Ibid.  28,  2967. 

3  P.  Sisley,  Bull.  Soc.  Chim.  III.  n,  562.     Z.  anal.  Ch.  34,  466. 


DETERMINATION  OF  HYDROXYL.        21 

again  boiling,  and  then  neutralizing,  the  process  being 
repeated  until  the  neutralized  liquid  ceases  to  become 
red  on  boiling;  this  shows  that  all  the  carbonates  are 
decomposed  and  no  loss  of  acetic  acid  need  be  appre- 
hended. It  has  been  suggested1  that,  after  the  hy- 
drolysis, elimination  of  the  alcohol,  and  acidification  by 
means  of  phosphoric  acid,  the  liquid  should  be  boiled 
in  a  reflux  apparatus  until  the  carbonic  anhydride  is  re- 
moved, the  subsequent  operations  being  similar  to 
those  above  described.  Sources  of  error  in  this  method 
are  described  on  p.  3O.2 

BENZOYL    DERIVATIVES. 

(I)    PREPARATION    OF    BENZOYL    DERIVATIVES. 

The  following  reagents  are  employed  for  the  intro- 
duction of  the  benzoyl  radicle  into  hydroxyl  com- 
pounds: 

Benzoyl  chloride; 

Benzole  anhydride,  sodium  bcnzoate; 

p-Brombenzoyl  chloride,  p-Brombenzoic  anhydride; 

o-Brombenzoyl  chloride; 

m-Nitrobenzoyl  chloride; 

PJienylsulpJionic  chloride. 

(A)  Preparation  of  Benzoyl   Derivatives   by  Means   of 
Benzoyl  Chloride. 

(a)  The  ' '  acid  ' '  method  consists  in  heating  the  sub- 
stance with  the  chloride  at  180°  during  several  hours 

1  P.  Dobrinei^  Z.  anal.  Ch.  34,  466,  foot-note. 

2  Cf.  G.  Goldschmiedt   and   R.  Jahoda,  M.  13,  53  ;  Goldschmiedt  and 
Hemmelmayr,  Ibid.  14,  214  ;  15,  319. 


22  RADICLES   IN   CARBON   COMPOUNDS. 

in  a  reflux  apparatus ;  it  is  not  advisable  to  employ  a 
sealed  tube  unless  there  is  assurance  that  the  hydro- 
chloric acid  will  not  cause  secondary  reactions  nor,  in 
the  case  of  nitrogenous  compounds,  combine  with  them 
to  form  hydrochlorides  which  would  then  cease  to 
react;1  when  this  may  occur  the  calculated  quantity  of 
chloride  is  employed,  and  the  heating  continued  during 
about  four  hours  at  ioo°-i  10°. 

(b)  The  preceding  method  has  been  largely  super- 
seded by  the  use  of  the  chloride  in  dilute  aqueous  alka- 
line solution.2  It  has  been  widely  applied,3  is  usually 
known  as  the  Schotten-Baumann  method,  and  seldom 
fails  to  give  good  results.  The  substance  is  well 
shaken  with  sodium  hydroxide  solution  (10$)  and  ben- 
zoyl  chloride  in  excess  until  the  smell  of  the  latter  is 
no  longer  noticeable.4  If  the  benzoylation  is  to  be  as 
complete  as  possible  more  concentrated  alkali  should  be 
used,  say  fifty  parts  of  sodium  hydroxide  solution  (20$) 
and  six  parts  of  the  chloride  in  a  closed  flask.5  The  tem- 
perature should  not  exceed  25°,6  and  it  is  frequently  de- 
sirable to  add  the  alkali  and  chloride  alternately  little  by 
little,  whilst  in  some  cases  the  former  must  be  highly  di- 
lute (o.25$).7  It  has  also  been  found  to  be  advisable  to 
use  the  reagents  in  the  proportion  of  seven  molecules 
of  soda  and  five  of  the  chloride  to  each  hydroxyl  ;8  the 
alkali  is  dissolved  in  water  (8-10  parts),  and  the  shak- 
ing and  gentle  cooling  continued  for  10-15  minutes. 

1  Danckwortt,  Arch.  Pharm.  228,  581. 

2  Lessen,   Ann.  161,    348  ;  175,  274.  319  ;  205,   282  ;  217,  16  ;  265, 
148,  foot-note. 

3  Baumann,  B.  19,  3218.  *  Baumann. 

5  Panormow,  B.  24,  R.  971.  6  v.  Pechmann,  Ibid.  25,  1045. 

7  B.  31,  1598.  8  Skraup,  M.  10,  390. 


DETERMINATION  OF  HYDROXYL.        23 

Hexabenzoylruberythric  acid  is  obtained  by  use  of  a 
10  per  cent,  sodium  hydroxide  solution  but  a  solution 
1:8  yields  a  heptabenzoyl  derivative.1.  For  experi- 
ments with  pyragallol  the  flask  must  be  filled  with  coal- 
gas  ;  in  the  case  of  substances  which  are  unstable  in 
presence  of  caustic  alkali,  sodium  carbonate,2  bicar- 
bonate, or  sodium  acetate  may  be  used.3  In  some 
cases  it  is  advantageous  to  dissolve  the  substance  in 
pyridine  and  then  add  the  benzoyl  chloride ;  occasionally 
a  higher  acyl  derivative  is  obtained  in  this  manner  than 
by  the  use  of  sodium  hydroxide.  The  method  is  par- 
ticularly well  adapted  to  bodies  which  are  unstable  in 
presence  of  alkali.4  The  precipitated  benzoyl  deriva- 
tives are  usually  white  and  semi-solid,  and  gradually 
harden  and  crystallize  by  prolonged  contact  with 
water;  often  traces  of  benzoyl  chloride  or  benzoic 
acid  are  retained  with  great  tenacity.  For  the  purifi- 
cation of  the  benzoyl  derivative  of  glucose5  it  was 
necessary  to  dissolve  out  the  crude  product  with  ether; 
this  was  distilled  off,  and  the  residue  treated  with  alco- 
hol, which  decomposed  the  last  portions  of  benzoyl 
chloride  that  had  not  been  removed  by  prolonged  shak- 
ing of  the  ethereal  solution  with  concentrated  alkali. 
The  alcoholic  liquid  was  treated  with  soda  in  excess, 
precipitated  with  water,  and  the  alcohol  and  ethylic 
benzoate  removed  by  means  of  steam.  The  residue 
was  then  repeatedly  recrystallized ;  at  first  from  alco- 
hol, then  from  glacial  acetic  acid.  The  pure  com- 

1  Schunck  and  Marchlewski,  Journ.  Chem.  Soc.  65  (1894),  187. 
-  Lessen,  Ann.  265,  148. 

3  Bamberger,  M.  &  J.,  II. ,  p.  546      E.  Fischer,  B.  32  (1899),  2454. 

4  A.  Einhorn  and  F.  Holland!.  Ann.  301  (1898),  95. 

5  Skraup,  M.  10,  395. 


54  RADICLES   IN  CARBON   COMPOUNDS. 

pound  is  insoluble  in  ether,  whilst  the  crude  preparation 
readily  dissolves.  Benzoic  acid  may  be  frequently  re- 
moved by  sublimation  in  vacuo,  or  by  extraction  with 
boiling  carbon  bisulphide.1  Repeated  extraction  with 
alkali  is  usually  effective  for  the  purification  of  benzoyl 
derivatives  soluble  in  ether,  but  it  may  produce  partial 
hydrolysis.  Derivatives  insoluble  in  ether  may  be  ex- 
tracted with  this  in  order  to  remove  excess  of  benzoyl 
chloride  and  benzoic  anhydride.2  Commercial  benzoyl 
chloride  often  contains  chlorobenzoyl  chloride,3  and 
since  the  chlorobenzoyl  derivatives  are  less  soluble 
than  the  benzoyl  derivatives,  recrystallization  is  not 
adequate  to  secure  a  product  free  from  chlorine.  It 
appears  also  that  pure  benzoyl  chloride  may  yield 
chloro-derivatives.4  Benzotrichloride  may  contain 
benzal  chloride ;  during  the  conversion  of  the  former 
into  benzoyl  chloride  by  the  action  of  lead  oxide  or 
zinc  oxide  the  latter  may  yield  benzaldehyde,  the 
presence  of  which  would  cause  complications.5  Lac- 
tones  often  yield  benzoyl  derivatives  of  acids  which  are 
soluble  in  alkali ;  they  are  separated  by  acidifying  and 
removing  the  benzoic  acid  from  the  precipitate  by 
steam  distillation.^ 

Schotten-Baumann's  method  has  also  been  applied 
to  the  preparation  of  acetyl  derivatives,  but  with  com- 
paratively little  success  on  account  of  the  greater  in- 
stability of  acetyl  chloride  in  the  presence  of  alkali  or 
water.7 

1  Barth  and  Schreder,  M.  3,  800.         2  M.  Jaffe,  B.  35  (1902),  2899. 

3  V.  Meyer,  B.  24,  4251.     Goldschmiedt,  M.  13,  55,  foot-note. 

4  B.  29,  2057.  &  Hoffmann  and  V.  Meyer,  Ibid.  25,  209. 
6  Ibid.  30,  127.  7  Ibid.  27,  3183. 


DETERMINATION  OF  HYDROXYL.       2$ 

(V)  Benzoyl  derivatives  may  also  be  prepared  in 
ethereal  or  benzene  solution,  with  the  help  of  dry  alkali 
carbonate,1  or  of  tertiary  bases  such  as  quinoline,  pyri- 
dine,  or  dimethyl  aniline.2  (Cf.  p.  7.) 

(d)  Sodium  ethoxide3  may  also  be  employed  for  the 
decomposition  of  benzoyl  chloride,  and  it  was  only  in 
this  manner  that  the  benzoyl  derivative  of  diacetylace- 
tone  could  be  obtained.4  The  ketone  was  heated  in  a 
reflux  apparatus  during  six  hours,  with  two  molecular 
proportions  each  of  benzoyl  chloride  and  sodium 
ethoxide,  which  had  been  dried  at  200°;  after  cooling, 
the  sodium  chloride  and  benzene  were  removed,  the 
residue  dissolved  in  ether,  and  the  solution  shaken 
with  dilute  alkali. 

(c)  Pyridine  or  quinoline  may  be  used  in  place  of 
aqueous,  or  alcoholic  alkali.5  The  product  is  triturated 
with  dilute  hydochloric  acid  and  recrystallized  from 
alcohol.  Vide  also  p.  147. 

(B)    Preparation  of  Benzoyl  Derivatives   from   Benzoic 
Anhydride. 

(a)  The  hydroxyl  compound  is  heated  with  benzoic 
anhydride,  in  an  open  vessel,  at  150°  during  1-2 
hours.6  This  is  often  preferable  to  method  b.1 

(ft)  In  some  cases  the  use  of  benzoic  anhydride  and 
sodium  benzoate  produces  a  more  complete  acylation 

1  Hoffmann  and  V.  Meyer,  B.  27,  3183. 

2  L.  Claisen,  Ibid.  31,  1023. 

3  L.  Claisen. 

4  Feist,  B.  28,  1824. 

5  Deninger,  Hid.   28,  1322  ;  A.  Einhorn  and  F.   Hollandt,  Ann.  301, 
(1898)  95- 

6  Liebermann,  Ann.  169,  237. 

7  L.  Sherman  Davis,  Arch.  Pharrn.  235  (1897),  213. 


26  RADICLES    IN   CARBON   COMPOUNDS. 

than  Schotten-Baumann's  method.1  As  an  example 
of  its  use,  scoparin  (2  grams),  benzoic  anhydride  (10 
grams),  and  dry  sodium  benzoate  (i  gram)  were  heated 
in  an  oil-bath  at  190°  during  six  hours;  the  product 
was  treated  at  the  ordinary  temperature  overnight  with 
aqueous  sodium  hydroxide  (2$),  and  the  precipitated 
hexabenzoyl  derivative  purified  by  means  of  alcohol. 

(C)  Preparation  of  Substituted  Benzoic  Acid  Derivatives 
and  of  Phenylsulphonic  Chloride. a 

(a)  Parabromobenzoyl  chloride. z  —  Parabromoben- 
zoic  acid  is  intimately  mixed  with  the  equivalent  quan- 
tity of  phosphorus  pentachloride,  and  warmed  until  the 
evolution  of  hydrogen  chloride  slackens.  The  product 
is  then  fractionated  under  reduced  pressure ;  the  pure 
compound  melts  at  42°,  boils  at  174°  (102  mm),  and 
is  readily  soluble  in  benzene  and  light  petroleum. 

(U)  Parabromobensoic  anhydride 4  is  prepared  by 
heating  sodium  parabromobenzoate  (3  parts)  with  para- 
bromobenzoyl  chloride  (2  parts)  at  200°  during  an 
hour.  It  melts  at  212°,  is  almost  insoluble  in  ether, 
carbon  bisulphide,  and  glacial  acetic  acid,  dissolves 
slightly  in  benzene,  and  is  purified  by  recrystallization 
from  chloroform. 

(c)  OrtJiobromobenzoyl  chloride 5  is  prepared  in  a  man- 
ner similar  to  its  isomer.  It  is  a  liquid,  boiling  at 
24i°-243°,  and  may  be  distilled  under  the  ordinary 
pressure  without  decomposition. 

1  Goldschmiedt  and  Hemmelmayr,  M.  15,  327. 

2  J.  J    Sudborough,  Journ.  Chem.  Soc.  67  (1899),  589. 

3  B    21,  2244.  *  Schotten  and  Schlomann,  Ibid.  24,3689. 
6  Ibid.  21,  2244.     Schopf,  Ibid.  23,  3436. 


DETERMINATION  OF  HYDROXYL.        2/ 

(a)  Metanitrobenzoyl  chloride^  is  formed  from  the 
nitrobenzoic  acid  by  gradually  and  intimately  mixing 
with  it  the  requisite  amount  of  phosphorus  pentachlo- 
ride ;  the  phosphorus  oxychloride  is  removed  by  dis- 
tillation, and  the  residue  fractionated  under  reduced 
pressure.  It  melts  at  34°  and  boils  at  183°- 184° 
(50-55  mm). 

(e)  Phenylsulphonic  chloride'2'  is  obtained  by  heating 
sodium  phenylsulphonate  with  phosphorus  penta- 
chloride  in  equivalent  proportion;  when  the  action 
ceases  the  product  is  poured  into  water,  the  oily  por- 
tion removed,  washed  with  water,  dissolved  in  ether, 
and  the  solution  decolorized  by  treatment  with  animal 
charcoal.  The  compound  melts  at  14°  and  boils  at 
120°  (10  mm). 

(D)  Acylation   by  Means    of    Substituted   Benzoic  Acid 
Derivatives  and  of  Phenylsulphonic  Chlorides. 

(a)  Parabromobenzoyl  chloride,  or  parabromobenzoic 
anylidride,  has  been  used  for  acylation,  the  number  of 
the  original  hydroxyl   groups  being  determined  from 
the  bromine  content  of  the  product.3 

(b)  Orthobromobenzoyl  chloride 4  and    mctanitroben- 
zoyl  chloride 5  are  also  well  adapted  for  the  determina- 
tion of  hydroxyl  groups. 

(c)  Phenylsulphonic  chloride 6  has  been  employed  for 

1  Claisen  and  Thompson,  B.  12,  1943. 

2  Otto,  Z.  f.  Ch.  1866,  fc>6. 

3  F.  Loring  Jackson   and  G.  W.  Rolfe,  Am.  Chem.  Journ.  9,  82;  B. 
20,  R.  524. 

4  Schotten,  Ibid.  21,  2250. 

5  Claisen  and  Thompson,  Ibid.  12,  1943.     Schotten.  Ibid.  21,  2244. 

6  Hinsberg,  Ibid.  23,  2962.     Schotten  and  Schlomann,  Ibid.  24,  3689. 


28  RADICLES   IN   CARBON   COMPOUNDS. 

the  same  purpose  ! ;  it  is  either  allowed  to  act  like  the 
benzoyl  chloride  in  the  Schotten-Baumann  method,  or 
it  is  warmed  with  the  hydroxyl  compound  (phenol) 
and  zinc  dust,  or  zinc  chloride.2 

Phenylsulphonic  derivatives  are  often  more  stable 
than  the  corresponding  benzoyl  compounds.3 

ANALYSIS  OF  BENZOYL  DERIVATIVES. 

(a)  The  exact  number  of  benzoyl  groups  in  many 
benzoyl  derivatives  is  shown  by  their  elementary  analy- 
sis; in  substitution  products  the  amount  of  haloid,  nitro- 
gen, or  sulphur  is  determined. 

(^)  The  following  method  has  been  suggested  for 
the  direct  determination  of  the  benzoic  acid : 4  The  sub- 
stance (about  0.5  gram)  is  hydrolysed  by  heating  it 
during  two  hours  at  100°,  in  a  sealed  tube,  with  con- 
centrated hydrochloric  acid  (10  parts),  which  has  been 
saturated  with  benzoic  acid  at  the  ordinary  tempera- 
ture. The  product  is  allowed  to  remain  1-2  days  at 
the  ordinary  temperature,  filtered  by  means  of  the 
pump,  and  the  precipitate  washed,  at  first  with  more 
of  the  hydrochloric  acid,  then  with  a  saturated  aqueous 
solution  of  benzoic  acid.  The  purified  benzoic  acid  is 
now  dissolved  in  N/io  sodium  hydroxide  solution  in 
excess,  titrated  with  excess  of  acid,  and  the  neutraliza- 
tion effected  with  the  needful  quantity  of  the  soda  solu- 
tion. The  latter  is  standardized  against  pure  benzoic 
acid,  phenolphthalein  being  employed  as  the  indicator. 
The  admixture  of  the  acid  and  water  during  the  wash- 

1  M.  Georgescu,   B.  24(1891),  416.       2  C.  Schiaparelli,  Gazz.  n,  65. 
3  B.  30,  669.  4  G.  Pum,  M,  12,  438. 


DETERMINATION    OF    HYDROXYL.  29 

ing  of  the  benzoic  acid  always  causes  a  precipitation  of 
benzoic  acid,  so  that  the  results  obtained  by  this 
method  are  invariably  about  I  per  cent,  too  high; 
therefore,  this  amount  must  be  deducted  from  the  per- 
centage of  acid  found,  or  the  exact  correction  ascer- 
tained by  means  of  a  blank  experiment  with  the  same 
quantities  of  liquids  as  have  been  used  in  the  main  one. 
(c)  A  method  of  more  general  application  consists 
in  separating  the  benzoic  acid  from  the  hydrolysed 
substance  by  means  of  a  current  of  steam,  and  titrating 
the  distillate  ;  l  its  principle  is  therefore  identical  with 
that  involved  in  the  determination  of  acetyl  groups, 
and  it  presupposes  that  the  compound  under  examina- 
tion is  completely  hydrolysed  by  alkalis,  and  yields  no 
acid,  other  than  benzoic,  volatile  with  steam.  The 
substance  (about  o.  5  gram)  is  mixed  with  alcohol 
(30-50  cc)  and  potassium  hydroxide  in  excess,  and 
heated  in  a  reflux  apparatus  ;  when  the  hydrolysis  is 
completed  the  product  is  cooled,  acidified  with  concen- 
trated phosphoric  acid  solution,  or  vitreous  phosphoric 
acid,  and  distilled  in  a  current  of  steam.  The  distilla- 
tion is  conducted  slowly  at  first,  and  alcohol  added,  if 
necessary,  by  means  of  a  dropping  funnel,  the  object 
being  to  secure  the  gradual  deposition,  in  a  crystalline 
state,  of  the  hydrolysis  products,  as  otherwise  resinous 
substances  might  surround  the  benzoic  acid  and  con- 
siderably hinder  its  volatilization.  When  the  distillate 
measures  I—  1.5  liters,  the  following  150  cc.  are  col- 
lected separately  and  tested  for  benzoic  acid  by  titra- 
tion,  and,  as  soon  as  it  is  no  longer  present,  the 


1  R.  and  H.  Meyer,  B.  28,  2965. 


OF  THE 
IJMi  wcrof* 


30  RADICLES    IN    CARBON   COMPOUNDS. 

distillation  is  stopped.  The  combined  distillate  is  ren- 
dered alkaline  with  a  known  quantity  of  N/io  sodium 
hydroxide  solution,  standardized  against  pure  benzoic 
acid,  and  evaporated  in  a  platinum,  silver,  or  nickel 
dish  to  a  volume  of  100—150  cc.,  when  the  excess  of 
alkali  is  titrated  back,  the  liquid  being  boiled  to  ex- 
pel carbonic  anhydride ;  this  may  be  regarded  as  accom- 
plished when  boiling  for  ten  minutes  produces  no 
change  in  the  indicator,  which  is  aurin  or  rosolic  acid. 
In  order  to  guard  against  the  production  of  sulphites 
and  sulphates,  the  concentration  of  the  alkaline  liquid 
is  carried  out  by  means  of  a  spirit  or  petroleum  lamp, 
unless  a  special  gas  burner  is  available. 

(//)  Benzoylmorphine  has  been  examined  by  direct 
titration.1  The  substance  was  dissolved  in  methylic 
alcohol,  mixed  with  a  little  water,  normal  sodium 
hydroxide  solution  (100  cc.)  added,  and  boiled  in  a 
reflux  apparatus  until  a  portion  of  it  gave  no  turbidity 
with  water;  titration  with  normal  hydrochloric  acid,  in 
presence  of  phenolphthalein,  showed  that  the  original 
compound  was  the  monobenzoyl  derivative.  The 
same  method  was  successfully  applied  to  the  analysis 
of  dibenzoylpseudomorphine  and  tribenzoylmethyl- 
pseudomorphine.  Vide  also  p.  148. 

ACYLATION    BY    MEANS    OF    OTHER    ACID 
RADICLES. 

Propionic  anhydride,  isobutyric  anhydride,  opianic 
acid,2  stearic  anhydride,3  and  phenylacetyl  chloride 

1  Vongerichten,  Ann.  294,  215.     Cf.  Knorr,  B.  30,  917-920. 
*  B.  31,  358.  3  Ann.  262,  5. 


DETERMINATION  OF  HYDROXYL.        31 

are  sometimes  used  for  acylation,  as  their  relatively 
high  boiling  points  facilitate  their  reaction  with  the 
hydroxyl  compound. 

(a)  Propionyl  derivatives  are  prepared  by  heating 
the  substance  with  propionic  anhydride,  in  a  stout, 
closed  bottle,  at  100°  during  two  hours;  an  open  ves- 
sel may  also  be  employed,  and  the  reaction  started  by 
the  addition  of  a  drop  of  concentrated  sulphuric  acid.1 

(£)  Isobutyryl  derivatives  are  prepared  in  a  similar 
manner.  Isobutyryl  ostruthin  was  prepared  by  heating 
ostruthin  (3  grams)  with  isobutyric  anhydride  (10 
grams)  in  a  sealed  tube  at  150°  during  3  hours.  The 
product  was  poured  into  water,  allowed  to  remain  until 
it  became  crystalline,  washed  with  warm  water  until 
neutral,  pressed,  dried  by  means  of  filter  paper,  and 
recrystallized  from  alcohol.2 

(c)  Phenylacetyl  chloride  is  prepared  3  by  adding  the 
acid,  in  chloroform  solution,  to  well-cooled  phosphorus 
pentachloride,  and  is  used4  like  benzoyl  chloride  in 
Schotten-Baumann's  method,  the  substance  being 
dissolved  in  dilute  aqueous  potassium  hydroxide  solu- 
tion, and  well  shaken  with  excess  of  the  chloride. 

(d  )  The  extent  to  which  phosphoric  acid  may  prove 
useful  remains  at  present  undetermined.5  Vide  also  p. 
148. 

ALKYLATION  OF  HYDROXYL  GROUPS. 

The  hydroxyl  of  phenol  and  primary  alcohols  is 
capable  of  alkylation,  and  the  number  of  alky  1  groups 

1  Arch.  Pharm.  228,  127;  Fortner  and  Skraup,  M.  15  (1894),  200 

2  Jassoy,  Ibid.  228,  551. 

3  B.  20,  1389;  29,  1986;  H.  Metzner,  Ann.  298  (1897),  375. 

*  Hinsberg,  B.  23,  2962.  5  Ibid.  30,  2368;  31,  1094. 


32  RADICLES    IN    CARBON    COMPOUNDS. 

introduced  may  be  determined  from  the  resulting  ethers 
by  Zeisel's  method  (cf.  p.  38).  As  a  rule,  the  phenolic 
ethers  are  not  hydrolysed  by  alkalies  (cf.  p.  53),  hence 
it  is  possible  to  differentiate  between  the  hydroxyl  and 
carboxyl  of  the  hydroxy  acids.  It  has,  however, 
been  shown  that  the  use  of  potassium  hydroxide  and 
alkyl  iodides  may  lead  to  the  production  of  compounds 
with  the  alkyl  directly  linked  to  carbon,1  and  that,  on 
the  other  hand,  hydroxyl  in  the  ortho  position  relative 
to  carbonyl  oxygen  is  determinable  by  acylation,  but 
not  by  alkylation.2 

Dimethyl  sulphate  is  sometimes  preferable  to  methyl- 
iodide  for  the  alkylation  of  phenols  and  all  other 
classes  of  compounds  capable  of  alkylation.  With 
phenols  it  is  employed  in  alkaline  aqueous  solution  as 
in  the  Schotten-Baumann  method3  (cf  p.  22). 

Diazomethane  may  also  be  used  as  an  alkylating 
agent.4  Vide  also  p.  149. 

PREPARATION    OF    BENZYL    DERIVATIVES. 

Benzyl  ethers  of  phenols  are  prepared  by  heating 
the  latter  in  a  reflux  apparatus,  during  several  hours, 
with  the  calculated  quantities  of  sodium  ethoxide  and 
benzyl  chloride  in  alcoholic  solution ;  the  precipitated 
sodium  chloride  is  removed  by  filtration  from  the  hot 

1  Herzig  and  Zeisel,  M.  9,  217,  882;   10,  144,  735;  n,  291,  311,  413; 

14,  376. 

2  Graebe.  Ilerzig,  M.  5,  72.     Schunk  and  Marchlewsky,  Journ.  Chem. 
Soc.  65,  185.     Kostanecki,  B.  26,  71,  2901.      Perkin,  Journ.  Chem.  Soc. 
67,  995;  69,  801. 

3  F.  Ullmann  and  P.  Wenner,  B.  33  (1900),  2476. 

4  v.  Pechmann,  Ibid.  28,  856;  31,  64,  501,  Ch.  Ztg.  98,  142. 


DETERMINATION  OF  HYDROXYL.        33 

liquid,1  and  the  composition  of  the  ether  determined 
by  elementary  analysis.  Where  the  chloride  fails  to 
react,  either  in  the  manner  described,  OK  in  conjunction 
with  the  silver  salt  of  the  phenol,  benzyl  iodide  may 
be  employed  for  the  preparation  of  these  compounds. * 

ESTERIFICATION    OF    PHENOLS. 

Mono-,  di-,  and  trihydric  phenols  easily  yield  read- 
ily crystallizable  esters  with  phenylnitrocinnamic  or 
phenylcinnamic  acid,  in  presence  of  phosphoric  anhy- 
dride and  a  neutral  solvent.  The  reaction  increases 
in  energy  with  the  number  of  hydroxyl  groups  and 
therefore  a  solvent  of  high  boiling  point,  such  as 
toluene,  should  be  employed  with  tri-  and  dihydric 
phenols.  If  the  latter  are  in  excess  they  yield  only 
monoesters.3 

PREPARATION  OF  CARBAMATES  BY  MEANS 
OF  CARBAMYL  CHLORIDE. 

PREPARATION    OF    CARBAMYL    CHLORIDE.4 

Ammonium  chloride  is  placed  in  a  distillation  flask 
attached  to  a  long  and  wide  condenser,  heated  at  about 
400°  in  an  air  bath,  and  treated  with  a  current  of  car- 
bonyl  chloride,  dried  by  means  of  sulphuric  acid.  The 
carbamyl  chloride,  which  has  a  highly  offensive  smell, 
distils  over  and  condenses  to  a  colorless  liquid,  or  to 

1  Haller  and  Guyot,  C.  r.  116,  43. 

2  M.  &  J.  II. ,   p.  125.     K.  Auwers  and  A.  J.  Walker,  B.  31  (1899), 
3040. 

3  M.  Bakunin  Gazz.  34  (1902),  i.  178. 

4  Gattermann  &  G.  Schmidt.  B.  20,  858. 


34  RADICLES   IN    CARBON   COMPOUNDS. 

long,  broad  needles  melting  at  50°.  It  volatilizes  at 
6i°-62°,  and,  after  prolonged  standing,  polymerizes 
to  cyamelide,  for  which  reason  it  should  be  employed 
as  quickly  as  possible  after  its  preparation.  In  contact 
with  water  or  moist  air,  it  is  -hydrolysed  to  carbonic 
anhydride  and  ammonium  chloride. 

PREPARATION    OF  'CARBAMATES. 

Carbamyl  chloride  reacts  with  hydroxyl  derivatives 
in  accordance  with  the  equation: 

NH2.CO.C1  +  HO.R  ->  NH2.CO.OR  +  HC1, 

the  resulting  carbamates  crystallize  readily.1  It  is 
usually  only  necessary  to  mix  the  substances,  in  equiv- 
alent proportion,  in  ethereal  solution,  as  the  reaction 
generally  proceeds  quantitatively  at  the  ordinary  tem- 
perature ;  in  the  case  of  some  polybasic  phenols  gentle 
warming  is  requisite.  The  amount  of  nitrogen  in  the 
product  is  a  measure  of  the  number  of  hydroxyl  groups 
in  the  original  compound.  Great  excess  of  the  chloride 
should  not  be  used,  as  it  may  lead  to  the  production  of 
ethereal  allophanates,  NH2.CO.NH.CO.OR. 

PREPARATION      OF      DIPHENYLCARBAMYL 
CHLORIDE  (C6H5)2  N.CO  Cl. 

This  substance  has  been  found  especially  useful  in 
the  investigation  of  rhodinol  (geraniol).2  It  is  prepared 
by  dissolving  diphenylamine  (250  grams)  in  chloroform 
(700  cc),  adding  anhydrous  pyridine  (120  cc.),  and 

1  Gattermann,  Ann.  244,  38. 

2  Erdmann  and  Huth,  J.  pr.  53,  45. 


DETERMINATION  OF  HYDROXYL.        35 

passing  a  current  of  carbonyl  chloride  (147  grams) 
into  the  liquid,  which  is  maintained  at  o°.  After  re- 
maining during  5—6  hours,  the  chloroform  is  distilled 
off  on  the  water-bath,  and  the  residue  crystallized 
from  alcohol  (1.5  liters).  The  yield  is  300  grams, 
the  product,  after  recrystallization  from  alcohol  (i 
liter),  is  pure,  and  melts  at  84°. 1 

PREPARATION  OF  PHENYLCARBAMIC  ACID 
DERIVATIVES. 

PREPARATION    OF    PHENYLISOCYANATE.2 

Commercial  phenylurethane  (15  grams)  is  mixed  with 
phosphoric  anhydride  (30  grams)  in  a  small  retort,  and 
heated  by  means  of  a  luminous  flame,  a  large  distilla- 
tion flask  being  employed  as  receiver;  the  combined 
distillate  from  a  number  of  such  preparations  is  then 
fractionated  once.  The  isocyanate  boils  at  169°  (769 
mm),3  and  the  yield  is  52-53  per  cent.4 

ACTION      OF      PHENYLISOCYANATE      ON      HYDROXYL 
DERIVATIVES.5 

Ethereal  phenylcarbamates  are  formed  by  the  inter- 
action of  hydroxyl  compounds  and  phenylisocyanate  in 
equimolecular  proportion  in  accordance  with  the 
equation: 

ROH  +   C6H5N:CO->C6H5NH.CO.OR. 

1  J-  pr-  56,  7- 

2  H.  Goldschmiedt,  B.  25,  2578,  foot-note. 
8  Hofmann,  Ibid.  18,  764. 

*  Zanoli,  Ibid.  25,  2578,  foot-note. 

5  Hofmann,  Ann.  74,  3;  B.  18,  518.     Snape,  Ibid.  18,  2428. 


36  RADICLES    IN   CARBON    COMPOUNDS. 

The  reaction  often  proceeds  at  the  ordinary  tempera- 
ture, but  it  is  best  to  mix  the  compounds  in  the  re- 
quisite proportion,  and  boil  them  rapidly  by  means  of  a 
previously  heated  sand-bath,  and  complete  the  reac- 
tion by  shaking  and  gentle  warmth.1  Polybasic  phe- 
nols are  heated  in  a  sealed  tube  for  10-16  hours; 2  if  the 
compound  eliminates  water  at  this  temperature  the 
phenylisocyanate  is  converted  by  it  into  carbonic  an- 
hydride and  carbanilide.3  The  duration  of  the  boiling 
in  an  open  vessel  should  be  shortened  as  much  as  pos- 
sible to  reduce  the  production  of  diphenylcarbamide. 
When  cold  the  product  of  the  reaction  is  treated  with 
a  little  benzene  or  ether  to  dissolve  unaltered  phe- 
nylisocyanate, then  washed  with  cold  water,  and  re- 
crystallized  from  alcohol,  ethylic  acetate,  or  a  mixture 
of  ether  and  light  petroleum,  which  leaves  the  sparingly 
soluble  diphenylcarbamide  undissolved. 

a— 2-Acetylangelica  lactone  reacts  slowly  with  phe- 
nylisocyanate at  the  ordinary  temperature.  After  14 
days  the  product  is  boiled  out  with  benzene  to  sep- 
arate it  from  /5-derivate  and  precipitated  by  means  of 
light  petroleum.  It  is  decomposed  by  alcohol.4 

The  presence  of  negative  groups  in  the  molecule  of 
the  hydroxyl  derivative  hinders,  or  completely  prevents, 
the  reaction;  thus  trinitrophenol  gives  no  derivative 
when  heated  at  180°  under  pressure.5  Ketodibenzoyl- 
methane  also  fails  to  form  a  urethane  but  yields  a 

1  Tessmer,  B.  18,  969. 

2  Snape,  Ibid.  18,  2428. 

3  Tessmer,  Ibid.  18,  969.     Beckmann,  Ann.  292,  16. 

4  L.  Knorr  and  W.  A.  Caspari.  Ibid.  303  (1898),  141. 

5  Gumpert,  J.  pr.  31,  119;  32,  278. 


DETERMINATION  OF  HYDROXYL.        37 

small  amount  of  triphenylisocyanurate.1  An  anomal- 
ous action  of  phenylisocyanate  has  been  described.2 

Phenylisocyanate  combines  with  certain  mercap- 
tans,  forming  compounds  with  the  group  SH  analogous 
to  those  yielded  with  hydroxyl  derivatives,  hence,  in 
dealing  with  sulphur  derivatives,  the  results  obtained 
from  its  use  must  be  interpreted  with  caution.  Vide 
also  p.  150. 

An  attempt  has  been  made  to  determine  the  pres- 
ence of  hydroxyl  groups  by  the  use  of  i  :  2  :  4-chlor- 
dinitrobenzene.4 

Organic  magnesium  derivatives  react  with  many 
hydroxyl  derivatives  in  accordance  with  the  equation 
CH3MgI  +  R.OH  <z>CH4+RO.MgI.  The  products  are 
frequently  crystalline.  The  reaction  is  carried  out  in 
presence  of  anhydrous  ether,  and  is  useful  for  the 
identification  of  hydroxyl  derivatives,  and  their  separa- 
tion from  mixtures  of  hydrocarbons,  etc.5  Vide  also 
p.  152. 

1  J.  Wislicenus,  Ann.  308  (1899),  233. 

2  U.  Eckart,  Arch.  Pharm.  229  (1891),  369. 

3  H.  Goldschmidt  and  A.  Meissler,  B.  23  (1890),  272. 

4  Vongerichten,  Ann.  294,  215. 

5  L.  Tschugaeff,  B.  35  (1902),  3912. 


CHAPTER  II. 

DETERMINATION      OF      METHOXYL,      CH3O-,      ETHOXYL, 
C2H50-,  AND   CARBOXYL,   CO.OH. 

DETERMINATION  OF  METHOXYL,  CH36-. 

s.  ZEISEL'S  METHOD.1 

This  method,  which  is  distinguished  for  beauty  and 
reliability,  depends  on  the  conversion  of  the  methyl  of 
the  methoxy  group  into  methyl  iodide  by  means  of 
hydriodic  acid,  the  methyl  iodide  being  then  decom- 
posed by  alcoholic  silver  nitrate  solution  into  silver 
iodide.  The  original  apparatus,  represented  in  Fig.  2, 
consists  of  a  reversed  condenser  K,  through  which 
water  at  4O°-5O°  flows;  at  the  lower  end  a  flask  A  of 
30-35  cc.  capacity  is  attached  by  means  of  a  cork;  the 
flask  has  a  side  tube  sealed  on, through  which  a  current 
of  carbonic  anhydride  may  be  passed.  A  Geissler's 
potash  bulb  is  connected  to  the  upper  end  of  the  con- 
denser, also  by  means  of  a  cork;  it  contains  0.25-0.5 
gram  red  phosphorus  suspended  in  water,  and  is 
maintained  at  a  temperature  of  5O°-6o°  by  the  water- 
bath  in  which  it  is  placed.  Its  object  is  to  absorb  any 

iM.  6,  989;  7,406. 

38 


METHOXYL,    ETHOXYL,    AND  CARBOXYL. 


39 


iodine  or  hydriodic  acid  which  might  be  carried  over 
by  the  methyl  iodide   vapor.      The   two   flasks   which 


complete  the  apparatus  have  a  capacity  of  80  cc.  each; 
the  first  contains  50  cc.  of  alcoholic  silver  nitrate  solu- 
tion, the  second  25  cc. ;  they  are  connected  by  means 


4O  RADICLES   IN    CARBON    COMPOUNDS. 

of  corks,  and  may  be  conveniently  replaced  by  two 
distillation  flasks,  the  side  tube  of  the  first  being  bent 
downwards  at  a  right  angle  into  the  second.  A 
modified  apparatus,  Fig.  3,  has  been  described,  which 


FIG.  3. 

serves  as  a  combined  condenser  and  washing  arrange- 
ment.1 The  flask  A  contains  the  substance  and  hydri- 
odic  acid,  the  bulbs  //  and  ///  red  phosphorus  and 
water,  and  B  and  D  the  silver  nitrate  solution.  A  sec- 
ond form  of  apparatus  has  a  very  convenient  appliance 

1  Benedikt  and  Grussner,  Ch.  Ztg.  13,  872. 


METHOXYL,    ETHOXYL,    AND   CARBOXYL.          4! 

for  heating  and  supplying  the  water  to  the  condenser.1 
Modified  boiling  flasks,2  (Fig.  4)  which    pre- 
vent the  action  of  the  heated  hydriodic*  acid 
on  the  cork,  have  been  designed. 

Fig.  5  shows  a  later  and  better  form  of 
Ziesel's  apparatus3  and  is  self  explanatory. 
The  connections  are  of  ground  glass  with 
springs  and  rims  to  make  water  joints. 
The  flasks  E  and  F  are  provided  with  marks 
about  half-way  up  to  indicate  45  and  5  cc  re- 
spectively. If  the  substance  under  examination  is 
not  volatile,  the  condenser  may  be  replaced  by  a  verti- 
cal tube  bent  back  in  a  U  shape.  The  method  is  not 
applicable  to  compounds  containing  sulphur,  and  the 
hydriodic  acid  employed  must  not  have  been  prepared 
by  means  of  hydrogen  sulphide,  otherwise  it  is  difficult 
to  free  it  completely  from  volatile  sulphur  compounds, 
the  presence  of  which  would  be  apt  to  cause  the  forma- 
tion of  mercaptans  and  silver  sulphide.  C.  A.  F. 
Kahlbaum,  of  Berlin,  supplies  "hydriodic  acid  for 
methoxyl  determination,"  which  is  prepared  by  means 
of  phosphorus,  and  is  trustworthy.  Should  a.  blank  ex- 
periment show  that  the  hydriodic  acid  produces  a  per- 
ceptible precipitate  in  the  silver  nitrate  solution,  it  must 
be  purified  by  distillation,  the  first  and  last  quarters  of 
the  distillate  being  rejected;  it  should  have  a  sp. 
gr.  =  1.68  —  1.72.  Boiling  the  acid  with  a  reversed 
condenser,  even  during  several  days,4  does  not  suffice 

1  L.  Ehmann,  Ch.  Ztg.  14,  1767;  15,  221. 

2  Benedikt,  Ibid.  13,  872.     M.  Bamberger,  M.  15,  505. 

3  Made  by  Paul  Haack  of  Vienna. 

4  Benedikt. 


42  RADICLES    IN   CARBON    COMPOUNDS. 

for  its  purification.  The  silver  nitrate  solution  is  pre- 
pared by  dissolving  the  fused  salt  (2  parts)  in  water  (5 
parts),  and  adding  absolute  alcohol  (45  parts) ;  it  is 


FIG.  5. 

kept  in  the  dark,  and  the   quantity  required  for  each 
determination  filtered  into  the  absorption  flasks. 

I.    METHOD    FOR    NON-VOLATILE    SUBSTANCES. 

After   the   apparatus     is   put   together,    tested,    and 
found  to  be  air-tight,   the  silver  nitrate  solution  is  in- 


METHOXYL,    ETHOXYL,    AND   CARBOXYL.          43 

troduced  into  the  absorption  flasks,  and  the  substance 
(0.2-0.3  gram)»  together  with  the  hydriodic  acid  (10 
cc.),  placed  in  the  distillation  flask;  unless  Bamberger's 
pattern  is  employed  this-  should  also  contain  a  few 
pieces  of  porous  plate  to  regulate  the  ebullition ;  it  is 
then  heated  to  boiling  in  a  glycerin-bath.  During 
this  time  the  current  of  carbonic  anhydride  is  passed 
through  the  apparatus  at  the  rate  of  three  bubbles  in 
two  seconds.  The  gas  employed  must  be  washed 
with  water,  and  also  with  silver  nitrate  solution,  to  re- 
move any  hydrogen  sulphide  arising  from  impurities  in 
the  marble.  The  warm  water  must  also  be  supplied 
to  the  condenser  and  the  bath  containing  the  potash 
bulbs.  Some  10-15  minutes  after  the  acid  begins  to 
boil  the  silver  nitrate  becomes  turbid  and  soon  a  white 
double  compound  of  silver  nitrate  and  silver  iodide  pre- 
cipitates in  the  first  flask;  the  liquid  in  the  second  one 
usually  remains  clear,  but  sometimes  becomes  opales- 
cent if  the  current  of  carbonic  anhydride  is  very  rapid, 
or  the  substance  particularly  rich  in  methoxyl  groups; 
these  conditions  may  also  cause  the  precipitate  to  be- 
come yellow.  The  conclusion  of  the  experiment  is 
readily  indicated  by  the  complete  subsidence  of  the 
precipitate,  which  becomes  crystalline;  the  time  re- 
quired is  1—2  hours.  The  tubes  and  flasks  with  the 
silver  solution  are  disconnected,  and  the  second  one 
diluted  with  five  parts  of  water;  if  no  precipitate  ap- 
pears after  remaining  several  minutes  nothing  more  is 
done  to  it,  otherwise  it  is  added  to  the  contents  of  the 
first  flask,  which  are  poured  into  a  beaker,  any  precipi- 
tate adhering  to  the  tubes  is  removed  to  the  beaker  by 
means  of  a  feather  and  jet  of  water;  the  volume  is  now 


44  RADICLES    IN   CARBON   COMPOUNDS. 

made  up  to  about  500  cc.  with  water,  evaporated  to  one 
half  on  the  water-bath,  then  water  and  a  drop  of  nitric 
acid  added,  and  the  liquid  digested  until  the  silver 
iodide  is  completely  precipitated;  it  is  then  filtered  and 
weighed  in  the  usual  manner.  The  precipitate  adher- 
ing to  the  tubes  is  usually  dark-colored,  possibly  from 
the  presence  of  a  trace  of  phosphorus,  but  this  does  not 
affect  the  accuracy  of  the  determination.  100  parts  of 
silver  iodide  =  13.20  parts  of  CH3O  =  6.38  parts  of 
CH3.  The  method  is  applicable  to  compounds  con- 
taining chlorine,  bromine,1  or  nitro-groups,  but  not  to 
sulphur  compounds.2  In  the  case  of  nitro-derivatives, 
or  other  compounds  which  readily  liberate  iodine  from 
hydriodic  acid,  it  is  desirable  to  place  a  little  red  phos- 
phorus in  the  boiling-flask.  The  potash  bulbs  require 
refilling  after  four  or  five  determinations.  Hydriodic 
acid  causes  many  substances  to  become  resinous,  and 
the  resin  may  protect  a  portion  of  the  methoxy  com- 
pound from  the  action  of  the  acid.  This  difficulty 
is  overcome  by  adding  acetic  anhydride  (6-8  volumes 
per  cent)  to  the  acid,  as  was  shown  in  the  case  of 
methyl  and  acetylethylquercetin,  rhamnetin,  and 
triethoxypbloroglucinol.3  The  method  is  also  well 
adapted  for  the  determination  of  alcohol  of  crystal- 
lization.4 


1  G.  Turn,  M.  14,  498. 

2  Zeisel,  Ibid.  7,  409.     Benedikt  and  Bamberger,  Ibid.  12,  I. 

3  Herzig,  Ibid.  9,  544.     Cf.   Pomeranz,  Ibid.  12,  383. 

4  J.  Herzig  and  H.  Meyer,  Ibid.  17,  437. 


METHOXYL,    ETHOXYL,    AND    CARBOXYL.          45 


2.    MODIFICATIONS     OF     THE     METHOD     FOR    ITS   USE 
WITH   VOLATILE    COMPOUNDS. 

Volatile  substances  may  usually  be  treated  in  the 
manner  described  above  if,  at  the  commencement  of 
the  experiment,  a  slow  stream  of  carbonic  anhydride 
is  employed  and  cold  water  run  through  the  condenser. 
The  following  special  modifications  for  particularly 
volatile  compounds  have  been  suggested.1  The  sub- 
stance (0.1-0.3  gram)  is  sealed  into  a  small  bulb  of 
thin  glass,  which  is  sealed  up  in  a  larger  tube  together 
with  hydriodic  acid  (10  cc.,  sp.  gr.  —  1.7)  and  a  piece 
of  heavy  glass  about  2  cm  in  length  with  a  sharp 
corner.  The  heavy  glass  is  to  assist  in  breaking  the 
bulb  with  the  substance  before  the  heating,  but  is  un- 
necessary if  the  latter  is  enclosed  in  test-tube  glass 
with  a  long  capillary.  The  larger  tube  is  30-35  cm 
long  and  1.2—1.5  cm  inner  diameter;  both  ends  are 
drawn  out,  the  one  to  fit  into  a  tube  10  cm  long  and 
1-2  cm  inner  diameter,  which  is  sealed  to  a  wider' 
tube,  the  other  so  that  a  piece  of  stout  rubber  tube  will 
fit  over  it  quite  tightly.  The  drawn-out  ends  must  be 
strong  enough  to  resist  the  pressure  during  the  heat- 
ing, and  sufficiently  thin  to  be  readily  broken  after 
being  scratched  with  a  file.  The  substance  and  hydri- 
odic acid  are  heated  at  130°  during  two  hours,  then, 
when  cold,  one  point  of  the  tube  is  fitted  into  the  nar- 
row one  mentioned  above,  the  wide  portion  of  which 
passes  through  a  triply  bored  cork  into  a  wide-mouthed 
flask.  Into  the  second  opening  of  the  cork  the  con- 

1  Zeisel,  M.  7,  406. 


46  RADICLES    IN   CARBON   COMPOUNDS. 

denser  fits,  whilst  the  third  contains  a  piece  of  stout 
glass  rod  bent  to  a  Z  form ;  by  turning  this  the  drawn- 
out  end  of  the  heating-tube  is  broken.  The  contents 
are  transferred  to  the  flask  partly  by  shaking,  partly 
by  gently  warming;  the  upper  capillary  is  covered  with 
a  piece  of  rubber,  the  end  broken,  and  a  current  of 
carbonic  anhydride  immediately  passed  through  the 
apparatus.  The  determination  then  proceeds  in  the 
manner  already  described. 

3.    MODIFICATION   OF    ZEISEL'S    METHOD.1 

Instead  of  red  phosphorus  and  water  the  potash  bulbs 
contain  a  solution  consisting  of  arsenious  anhydride  (i 
part),  potassium  carbonate  (I  part),  and  water  (10 
parts).  The  bulbs  must  be  refilled  for  each  determina- 
tion to  prevent  the  apparatus  becoming  choked  with 
precipitated  anhydride,  but  this  is  compensated  for  by 
the  fact  that  not  the  slightest  reduction  (blackening)  of 
the  silver  nitrate  solution  takes  place.  The  N/io 
silver  nitrate  solution  is  made  by  dissolving  the  nitrate 
(17  grams), in  water  (30  cc.),and  diluting  to  a  liter  with 
commercial  absolute  alcohol,  its  titer  being  determined 
by  means  of  N/io  potassium  thiocyanate  solution. 
For  the  alkyloxyl  determination  the  silver  solution 
(75  cc.)  is  acidified  with  a  few  drops  of  nitric  acid,  free 
from  nitrous  acid,  and  divided  between  the  two  absorp- 
tion flasks.  At  the  conclusion  of  the  experiment  the 
silver  solution  with  the  precipitate  is  diluted  with  water 
to  250  cc,  cautiously  shaken,  filtered  by  means  of  a  dry 
ribbed  filter  into  a  dry  flask,  and  50  cc.  or  100  cc.  of  the 

1  J.  Gregor,  M.  19,  116. 


METHOXYL,    ETHOXYL,    AND   CARBOXYL.          47 

clear  filtrate  acidified  with  nitric  acid,  free  from  nitrous 
acid,  treated  with  ferric  sulphate  solution,  and  titrated 
in  the  ordinary  manner.1  (Cf.  p.  114.) 

It  has  been  stated  that  this  method  is  unreliable  on 
account  of  the  action  of  methylic  iodide  on  the  arsenical 
liquid2  but  further  investigation  shows  that  accurate  re- 
sults are  obtained  if  the  arsenious  solution  is  less  con- 
centrated.3 Vide  also  p.  154.  •  . 

METHOD   FOR  THE    DIFFERENTIATION  OF    METHOXYL 
AND     ETHOXYL. 

Zeisel's  method  does  not  distinguish  between  me- 
thoxyl  and  ethoxyl ;  should  this  be  necessary,  the  alkyl 
iodide  must  be  prepared  in  quantity  sufficient  for  its 
identification,  or,  if  possible,  Lieben's  iodoform  test 
must  be  applied.  For  the  differentiation  of  the  alkyls 
the  investigation  of  the  action  of  phenyl  isocyanate  on 
the  alkyloxy  derivatives  has  been  suggested.4  The 
compound  is  heated  with  phenyl  isocyanate,  in  equi- 
molecular  proportion,  at  150°,  during  several  hours,  in 
a  sealed  tube.  The  product  is  steam-distilled,  and  the 
volatile  portion  purified  by  recrystallization  from  a  mix- 
ture of  ether  and  light  petroleum  ;  methylphenylurethane 
melts  at  47°,  ethylphenylurethane  at  50°,  and  they 
can  be  further  distinguished  by  analysis. 

1  Volhard,  J.  pr.  9,  217.     Ann.  190,  I.     Z.  anal.  13,  171;   17,  482. 

2  J.  M.  van  Charante  Rec,  21  (1902),  38. 

3  Pribram,  private  communication. 

4  Beckmann,  Ann.  292,  9,  13. 


48  RADICLES    IN    CARBON    COMPOUNDS. 

DETERMINATION  OF  ETHOXYL  (C2H.6~). 

The  determination  of  ethoxyl1  is  carried  out  exactly 
in  the  manner  described  in  the  preceding  section  for 
methoxyl  except  that  the  water  in  the  condenser  and 
in  the  bath  surrounding  the  potash  bulbs  should  be 
heated  at  about  80°.  100  parts  of  silver  iodide 
=  19.21  parts  C2H.O  =  12.34  parts  C2H.. 

The  method  is  also  applicable  to  butyl  and  amyl 
ethers,  i.e.  to  the  determination  of  butoxyl  C4H9O, 
and  amoxyl  C5HnO.2  Vide  also  p.  155. 

DETERMINATION  OF  CARBOXYL  (CO.  OH). 

The  following  methods  are  employed  for  the  deter- 
mination of  the  basicity  of  organic  acids: 

(A)  Analysts  of  metallic  salts  of  the  acid. 

(B)  Titration. 

(C)  Esterification. 

(D)  Determination  of   the  electrolytic    conductivity 
of  the  sodium  salts. 

(E)  Indirect  methods: 

(1)  Carbonate  method. 

(2)  Ammonia  method. 

(3)  Hydrogen  sulphide  method. 

(4)  Iodine  method. 

It  is  easy  to  decide  which  of  these  methods  is  the 
most  suitable  for  any  special  case,  but  the  qualitative 
differentiation  between  carboxyl  and  phenolic  hydroxyl 

1  Zeisel,  M.  7,  406. 

2  S.   Zeisel  and    R.    Fanto,    Zeit.    landvv.  Versuchs.  Wes.   Oesterr.    5 
(1902),  729.     Journ.  Chem.  Soc.  82,  ii.  (1902),  in,  585. 


METHOXYL,    ETHOXYL,    AND    CARBOXYL.          49 

frequently  presents  difficulties  that  can  only  be  over- 
come with  certainty  by  the  preparation  of  the  amide 
and  its  conversion  into  the  nitrile. 

(A)   Determination  of  Carboxyl  by  Analysis  of  Metallic 
Salts  of  the  Acid. 

In  many  cases  the  number  of  carboxyl  groups  in  an 
organic  compound  may  be  determined  by  the  analysis 
of  its  neutral  salts;  of  these  the  silver  salts  are  usually 
the  most  appropriate,  as  they  are  generally  formed  di- 
rectly without  admixture  of  hydrogen  salts,  and  are 
almost  always  anhydrous.  Exceptions  to  this  rule  are, 
however,  encountered ;  thus  the  silver  salts  of  canthar- 
idinic  acid,1  camphoglycuronic  acid,3  and  metaquinal- 
dinic  acid 3  crystallize  with  one,  three  and  four 
molecules  of  water  respectively,  and  hydrogen  silver 
salts,4  though  not  of  frequent  occurrence,  are  known. 
Aromatic  hydroxymonocarboxylic  acids  containing 
two  nitre-groups  often  give  salts  containing  two  atoms 
of  silver.  As  examples  may  be  mentioned  3:5-dinitro- 
hydrocumaric,  1 :  3  :  5-dinitroparahydroxybenzoic,  and 
2  :  6-dinitro-5-hydroxy-3-4-dimethylbenzoic  acids.5 
Many  silver  salts  are  very  sensitive  to  light  or  air,  and 
some,  like  silver  oxalate6  and  silver  lutidonemonocar- 
boxalate7  are  explosive ;  for  the  analysis  of  such  the 

1  Homolka,  B.  19,  1083. 

2  Schmiedeberg  and  Meyer,  Z.  physiol.  Chem.  3,  433. 

3  Eckhardt,  B.  22,  276. 

4  A  list  of  them  is  given  in  Lassar-Cohn,  "  Manual  of  Organic  Chem- 
istry," translated  by  Alex.  Smith,  p.  345. 

5  W.  H.  Perkin,  Jun.,  Journ.  Chem.  Soc.  75  (1899),  176. 

6  B.  16,  1809. 

7  A.  P.  Sedgvvick  and  N.  Collie,  Journ.  Chem.  Soc.  67  (1895),  407. 


50  RADICLES    IN    CARBON   COMPOUNDS. 

compound  is  dissolved  or  suspended  in  water  or  acid, 
and  treated  with  hydrogen  sulphide  or  hydrochloric 
acid.  Silver  salts  which  do  not  explode  when  heated 
are  usually  analyzed  by  ignition  in  a  porcelain  crucible  ; 
if  the  residual  silver  contains  carbon  it  is  dissolved 
in  nitric  acid,  the  solution  diluted  and  filtered,  and  the 
silver  precipitated  by  means  of  hydrochloric  acid. 

Pyridine  and  quinoline  derivatives  and  amino-acids 
frequently  give  characteristic  copper  and  nickel  salts, 
whilst,  in  the  aliphatic  series,  the  zinc  salts  may  often 
be  usefully  employed.  Sodium,  potassium,  calcium, 
barium,  magnesium,  and,  less  frequently,  lead  salts 
are  also  sometimes  used  for  the  determination  of 
basicity,  but,  as  many  acids  do  not  yield  well-defined 
neutral  salts,  and  groups  other  than  carboxyl  can  ex- 
change hydrogen  for  metal,  the  method  has  not  a  very 
wide  application. 

(B)  Titration  of  Acids. 

The  basicity  of  a  carboxyl  derivative  may  often  be 
determined  by  titration  if  the  molecular  weight  of  the 
compound  is  known;  N/io  sodium  hydroxide,  potas- 
sium hydroxide,  or  barium  hydroxide  may  be  used  for 
the  titration  in  aqueous  solution,  or,  in  the  case  of  the 
first  two,  in  alcoholic  solution.  N/2  ammonium 
hydroxide  has  also  been  employed.1  The  acids  used 
are  .generally  hydrochloric  or  sulphuric,  but  the  latter 
is  unsuited  for  work  with  alcoholic  solutions,  as  the 
precipitation  of  insoluble  sulphates  prevents  a  correct 
observation  of  the  end  reaction.  The  liquid,  alcohol, 
ether,  etc.,  in  which  the  compound  under  examination' 
1  Haitinger  and  Lieben,  M.  0,  292. 


METHOXYL,   ETHOXYL,   AND  CARBOXYL.  51 

is  dissolved,  must  either  be  free  from  acids  or  must  pre- 
viously be  exactly  neutralized  by  means  of  N/io  alkali. 
Phenolphthalein,  methyl  orange,  rosolic  acid,  cur- 
cumin,  or  litmus,  are  usually  employed  as  indicators, 
the  first  two  more  frequently  than  the  others.  If  the 
liquid  is  dark  colored  the  use  of  "  alkali  blue  "  is  often 
convenient,  and  attention  must  always  be  paid  to  the 
possible  presence  of  carbonic  anhydride.  The  be- 
haviour of  various  acids,  hydroxy  acids,  phenols,  and 
their  substitution  products  with  helianthin,  phenol- 
phthalin,  and  Poirrier's  blue  has  been  studied.1  A 
somewhat  curious  and  interesting  attempt  has  been 
made  to  determine  the  neutrality  by  taste.2 

Certain  lactones  can  be  titrated  with  alkali  although 
they  are  insoluble  in  sodium  hydrogen  carbonate.3  a- 
Dibenzoylsuccinic  lactone  may  be  easily  titrated,  in 
alcoholic  solution,  with  iN  alkali  by  the  use  of  phenol 
phthalein.4  Hydroresorcinol  behaves  in  a  similar 
manner.5  Vide  also  p.  159. 

(C)  Esterification. 

In  very  many  cases  carboxylic  and  phenolic  hydrogen 
may  be  differentiated  by  the  esterification  of  the  corn- 
pound  with  alcohol  and  hydrogen  chloride.  It  has, 
however,  been  shown 6  that  acids  with  the  group 

1  H.  Imbert  and  A.  Astruc,  C.  r.  130  (1900),  35.     Journ.  Chem,  Soc. 
78  (1900),  i.  226. 

2  T.  W.  Richards,  Am.  Chem.  Journ.,  20,  125. 

3  H.  L.  Fulda,  M.  20  (1899),  700. 

4  L.  Knorr,  Ann.  293  (1897),  87. 

5  R.  v.  Schelling,  Ibid.  308  (1899),  185. 

6  V.    Meyer   and   others.       Many    papers    appeared   on   the   subject 
beginning  B.  27,  510,  and  ending  29,  2569. 


52  RADICLES   IN   CARBON    COMPOUNDS. 

C.COOH 
/\  (t  and  t'  —  tertiary  carbon  atom)  do  not  yield 

C      C 

t       t 

esters  with  alcohol  and  hydrogen  chloride  if  both  the 
carbon  atoms  marked  t  are  linked  to  Cl,  Br,  I,  or  NO2, 
while  the  groups  of  smaller  mass  F,  CH3,  OH  in  the 
same  positions  greatly  retard,  but  do  not  entirely  pre- 
vent, esterification.  On  the  other  hand,  certain  phe- 
nols such  as  phloroglucinol,1  which  gives  a  diether  and 
triether2,  hydroxyanthracene  (anthrol),  and  a-  and  fi- 
naphthol3,  yield  ethers  when  treated  with  hydrogen 
chloride  and  alcohol.  The  esterification  is  most  con- 
veniently carried  out  by  boiling  the  substance  for  3-5 
hours  in  a  reflux  apparatus  with  a  large  excess  of  ab- 
solute alcohol  containing  3-5  per  cent  of  hydrogen 
chloride  or  sulphuric  acid.4  Occasionally  alcohol  of 
95  per  cent  may  be  employed  if  more  sulphuric  acid  is 
used.5  Some  substances  form  additive  compounds 
with  alcohol  and  hydrogen  chloride.6  This,  as  also 
the  contamination  of  the  ester  by  traces  of  chlorine 
derivatives,  which  can  only  be  removed  with  difficulty, 
may  lead  to  confusion.  .  Certain  compounds  prepared 
from  carbamide  and  ethereal  dihydroxysuccinates  con- 
tain OH  groups ;  they  are  not  acids  but  they  readily 
etherify  with  hydrogen  chloride  and  ethylic  alcohol.7 

B.  17,  2106;  21,  603. 

J.  Herzig  and  H.  Kaserer  M.  21  (1900),  993. 
Liebermann  and  Hagen,  Ibid.  15,  1427. 
E.  Fischer  and  A.  Speier,  B.  28,  3252. 
Bishop  Tingle  and  A.  Tingle,  Am.  Chem.  Journ.  21,  243. 
Freund,  B.  32,  171. 
'  H.  Gersenheimer  and  R.  Anschiitz,  Ann.  306  (1899).  41,  54. 


METHOXYL,    ETHOXYL,    AND   CARBOXYL.          53 

The  esters  obtained  by  acid  or  alkaline  esterification 
are,  in  general,  distinguished  from  the  phenolic  ethers 
by  the  ease  with  which  aqueous  or  alcoholic  alkalis 
hydrolyse  them,  but  exceptions  are  known  since  trini- 
tromethoxybenzene  (methyl  picrate)  when  boiled 
with  concentrated  potassium  hydroxide  yields  methyl 
alcohol  and  potassium  picrate,1  and  methoxyanthracene 
(methyl  anthranol)  is  also  decomposed  by  boiling  with 
alcoholic  potash.2  Dimethyl  o-nitrocumarate  yields 
the  monoether  when  boiled  with  dilute  alkali,  the  acid 
is  only  formed  by  prolonged  heating  with  concen- 
trated alkali  in  excess.3  The  silver  salts  of  hydrox- 
amide  and  phenylhydroxamide  yield  ethylic  esters 
R.COH:N.OC2H5  which  behave  as  monobasic  acids 
when  titrated  with  caustic  alkalis.4  Vide  also  p.  159. 

The  composition  of  esters  is  determined  by  ele- 
mentary analysis,  and  the  alkyloxy  groups  by  the 
methods  described  in  the  earlier  portion  of  this  chapter. 
(Cf.  p.  38.) 

(D)  Determination  of  the  Basicity  of  Acids  by  means 
of  the  Electrolytic  Conductivity  of  the  Sodium 
Salts. 

It  has  been  shown  that  the  degree  of  electrolytic 
conductivity  of  the  sodium  salt  is  a  certain  indication 
of  the  basicity  of  the  corresponding  acid. 5  The  method 
is  of  very  general  application,  since  insoluble  acids 

1  Ann.  174,  259. 

2  Liebermann  and  Hagen,  B.  15,  1427. 

3  W.  v.  Miller  and  F.  Knikelin,  Ibid.  22  (1889),  1710. 

'4  R.   H.   Pickard,   C.  Allen,  W.   A.   Bowdler  and  W.  Carter,  Journ. 
Chem.  Soc.  81  (1902),  1565. 

5  Ostwald,  Z.  2,  901;  i,  74.    Walden,  Ibid,  i,  529;  2,  49. 


54  RADICLES   IN  CARBON   COMPOUNDS. 

usually  yield  sodium  salts  which  dissolve  in  water,  but 
it  fails  in  the  case  of  acids  which  are  so  feeble  that  their 
sodium  salts  are  hydrolysed  by  water  sufficiently  to 
impart  an  alkaline  reaction  to  the  solution.  The  fol- 
lowing apparatus  is  required  for  the  determination : 

(1)  A  small  induction  coil  (J,  Fig.  8),  such  as  is  em- 
ployed for  medicinal  purposes,  and  which  requires  only 
one  or  two  cells  for  prolonged  use.      The  spring  of  the 
interrupter  must  vibrate  rapidly  so  as  to  produce  a  high- 
pitched  sound  in  the  telephone,  as  this  is  more  easily 
heard  than  a  deeper  tone. 

(2)  A  bridge  consisting  of  a  scale  loocm.  in  length 
divided  into  millimeters;   along  it  stretches  a  wire  pro- 
vided with  a  sliding  contact.      The  wire  is  of  platinum, 
German  silver,  platinoid,  or  manganin,  the  last  is  the 
best   on   account   of    its    low  temperature    coefficient. 
The  wire  must  be  calibrated.1      For  high  resistances 
(1,000-200,000  Ohms)  the  special  form  of  resistance 
coil  described  by  Chaperon 2  should  be  used    instead 
of  the  wire.3 

(3)  A  rheostat  for  adjusting  the  resistance  (W,  Fig.  8). 
(4]  A  resistance  cell  for  the  electrolyte  (E,  Fig.  8). 

Kohlrausch's  form  (Fig.  6)  is  used  for  low  resist- 
ances, whilst  that  of  Arrhenius  (Fig.  7)  is  employed 
for  dilute  solutions  where  the  resistance  is  high.  The 
electrodes  must  be  platinised  by  filling  the  vessel  with 
a  dilute  solution  of  hydrochloroplatinic  acid  and  passing 

1  Strouhal  and  Barus,  Wied.  Ann.  10,  326.  The  method  is  also 
described  by  Jones,  "  Freezing-point,  Boiling-point,  and  Conductivity 
Methods."  Chem.  Pub.  Co.,  1897. 

1  C.  r.  108  (1894),  799. 

3  E.  Cohen,  L.  25  (1898),  16. 


FIG.  7. 


OF 


METHOXYL,    ETHCXYL,    AND  CARBOXYL.          gg 

a  current  of  4-5  volts.     The  direction  of  the  current 
is    changed    occasion- 
ally and    the    electro- 
lysis    continued     until 
both      electrodes     are 
completely        covered 
with    platinum    black ; 
this    requires    only    a   vS~r>/       -v^ 
short  time.      The  pla-       y  j, 

tinum  chloride   in   the  FIG.  6. 

cell  is  now  replaced 
by  sodium  hydroxide 
solution,  the  electrolysis  continued  for  a  few  mo- 
ments, the  electrodes  thoroughly  and  carefully 
washed  with  hydrochloric  acid,  and  finally  with  water. 
The  sodium  hydroxide  removes  all  chlorine,  which  is 
otherwise '  very  obstinately  retained  by  the  platinum. 
The  use  of  Lummer  and  Kurlbaum's  solution  for  plati- 
nising is  highly  recommended,  as  the  tone  minima  are 
much  more  distinct.1  The  solution  consists  of  plati- 
num chloride  (i  part),  lead  acetate  (0.008  part),  and 
water  (30  parts);  it  is  electrolysed  with  a  current 
density  of  0.03  amperes  per  sq.  cm,  the  direction  of 
the  current  being  frequently  changed  and  continued 
until  each  electrode  has  been  the  cathode  during  at 
least  fifteen  minutes. 

(5)  A  telephone.  Ostwald  states  that  the  most  sensi- 
tive ones  are  made  by  Ericsson  of  Stockholm,  but  for 
ordinary  purposes  a  Bell  instrument  is  sufficiently  good. 
In  using  it  the  unoccupied  ear  may  be  closed  with  cot- 
ton to  exclude  external  sounds. 


1  Kohlrausch,  Wied.  Ann.  1897,  p.  315;  E.  Cohen,  Z.  25,  1611. 


56  RADICLES    IN    CARBON    COMPOUNDS. 

(6)  A  water  batJi  with  stirrcr  and  thermometer,  or 
a  thermostat*^ 

The  apparatus  is  arranged,  in  the  form  of  Kirchhoff's 
modification  of  the  Wheatstone  bridge  (Fig.  8),  the  con- 
nections being  made  with  stout  copper  wire.  The  in- 
duction coil  is  enclosed  in  a  sound  tight  case,  or  is 

placed  in  another  room.  If 
determinations  of  solutions 
of  a  substance  at  different 
concentrations  are  to  be 
made,  the  solution  is  most 
conveniently  prepared  in 
the  resistance  cell  itself, 
portions  are  then  withdrawn  by  means  of  an  accu- 
rately calibrated  pipette,  and  the  desired  volume 
of  water  added,  which  has  previously  been  brought 
to  the  necessary  temperature  in  the  thermostat.  As 
a  rule  the  telephone  does  not  give  an  absolutely 
sharp  minimum  at  any  given  point,  but  it  is  easy 
to  find  two  limits  beyond  either  of  which  the  tone 
rises;  these  are  usually  separated  by  an  interval  of 
0.5-2  mm,  and  the  required  position  is  taken  as  mid- 
way between  them.  A  little  experience  enables  the 
observer  to  determine  the  conductivity  with  an  accu- 
racy of  o.i  per  cent.  If  the  tone  minimum  becomes 
indistinct  the  electrodes  must  be  replatinised.  The 
conductivity  is  calculated  from  the  measurements  by 

means  of  the  formula  /*  =  k.     —, ,  where 

iv .  u 


1  Ostwald,  Z.  2,  564,  where  also  a  good  description  of  the  other  parts 
of  the  apparatus  is  given. 


METHOXYL,    ETHOXYL,    AND   CARBOXYL.          57 

//  =  the  molecular  conductivity; 

v  —  the  volume  in  liters  of  the  solution  which  contains 

a  gram  molecule  of  the  electrolyte} 
w  =  the  adjusting  resistance ; 
a  =  the  length  of  wire  to  the  left  of  the  sliding  con- 

tact  (Fig.  8); 

b  =  that  to  the  right  of  the  contact  (Fig.  8) 
k  =  the  resistance  of  the  cell. 

The  value  of  k  is  determined  by  measuring  the  con- 
ductivity of  N/5O  solution   of  potassium   chloride,  for 
which  Kohlrausch  found  the  values : 
/*  =  112. 2  at  18°; 

yW   —     129.7    at   25°- 

Other   solutions   may   also   be   used.1     The  value  - 

a 

for  a  wire  1000  mm  in  length  has  been  calculated  by 
Obach  and  an  abbreviated  table  of  the  results  is  given 
in  the  appendix.  The  conductivity  of  the  water  em- 
ployed, which  should  be  as  highly  purified  from  dis- 
solved substances  as  possible,  is  determined  in  the 
same  manner  as  that  of  the  solution,  the  value  for  each 
liter  (v)  is  calculated  according  to  the  formula,  and 
subtracted  from  the  uncorrected  value  of  //.  For 
basicity  determinations  the  conductivity  is  usually  de- 
termined at  concentrations  of  one  gram  molecule  in  32 
and  1024  liters  respectively.  The  mean  difference  A 
between  these  values  is  as  follows: 

Monobasic  acids A  =  10.4—  i  x   10.4 

Dibasic  "     A  —  19.0  =  2  X     9-5 

Tribasic          "      A  =  30.2  =  3  X  10. 1 

Tetrabasic      "      ^/  =  41.  i  =:  4  x  10.3 

Pentabasic      "      A  =  50. 1  =  5  X  10 

1  Wiedemann  and  Ehert,  Physik.  Praktikum,  p.  389. 


58  RADICLES   IN   CARBON    COMPOUNDS. 

A  method  has  been  described  l  for  determining  the 
basicity  of  acids  based  on  the  alterations  which  they  ex- 
hibit in  electrolytic  conductivity  on  the  addition  of  alkali. 

Instead  of  the  telephone  and  induction  coil,  a  double 
commutator  and  a  galvanometer  may  be  used  to  de- 
termine the  electrolytic  conductivity,  the  commutating 
apparatus,  termed  a  secohmmeter,  is  so  arranged  that 
one  commutator  is  included  in  the  battery  circuit  and 
the  other  in  that  of  the  galvanometer;  on  rotating, the 
current  is  reversed  in  the  liquid  so  frequently  that  polari- 
zation is  annulled  and  the  galvanometer  commuted.2 

A  neat  form  of  apparatus3,  much  smaller  than  Kohl- 
rausch's,  consists  of  an  ebonite  cup  and  rod  fitted  with 
platinum  electrodes  prepared  in  the  usual  manner. 
The  rod  can  be  moved  vertically  over  the  cup  by 
means  of  micrometer  screws,  and  the  distance  between 
the  electrodes  read  off  on  a  divided  scale  by  a  vernier. 
Quantities  of  solutions  as  small  as  3  cc  maybe  employed. 

(E)  Indirect  Methods    for    the    Determination    of    the 
Basicity  of  Acids. 

These  methods  may  be  divided  into  four  classes  ac- 
cording to  the  nature  of  the  substance  liberated  by  the 
acid: 

(1)  Carbonate  method. 

(2)  Ammonia  method. 

(3)  Hydrogen  sulphide  method. 

(4)  Iodine -oxygen  method. 

1  D.  Berthelot,  C.  r.   112,  287. 

2  Cahart  and  Patterson,  '-Electrical  Measurements."  p.  109. 

3  R.  Goldschmidt  and  A.  Reychler,  Bull.  19  (1898),  iii.  675;  Journ. 
Chem.  Soc.  76  (1899),  ii.  463. 


METHOXVL,  ETHOXYL,  AND  CARBOXYL.       59 

(1)  Carbonate  Method. — The  substance  (0.5-1  gram) 
is  dissolved  in  water  in  a  flask  closed  by  a  rubber  stop- 
per with  three  holes.      In  one  hole  a  condensing  tube  is 
fitted,  which,  at  the  lower  end,  is  flush  with  the  stop- 
per while  the   upper  end  is  connected  with  an  absorp- 
tion apparatus  consisting  of  two  calcium  chloride  tubes 
and  potash  bulbs.      Through  the  second  hole  a  tube 
passes  to  the  bottom  of  the  flask,  the  end  being  drawn 
out  and  bent  upwards;  by  means  of  this  tube  a  current 
of  air,  free  from  carbonic   anhydride,  is  passed.      The 
third  hole  of  the  flask  is  closed  with  a  small  dropping 
funnel,  the  end  of  which  also  is  drawn  out  and  bent 
upwards,  being  run  below  the  liquid  in  the  flask.      The 
solution  of  the  acid  is  gently  boiled,  and  barium  car- 
bonate, in  the  form  of  a  thin  paste,  is  added  in  small 
quantities  by  means  of  the  funnel.      When  the  operation 
is  completed  the  apparatus  is  allowed  to  cool  in  a  cur- 
rent of  purified  air,  again  boiled,  cooled,  and  the  ab- 
sorption bulbs  weighed.1     A  similar  method,  based  on 
the  decomposition  of  sodium  hydrogen  carbonate,  has 
also  been  described.2 

(2)  Ammonia  Method. — The  acid  (about  I  gram)  is 
dissolved  in  excess  of  alcoholic   potassium  hydroxide, 
and    made    up   to    250   cc   with   alcohol   of   the  same 
strength   (93  per  cent).      The  excess  of  alkali  is  neu- 
tralized by  carbonic  anhydride,   the  precipitated   car- 
bonate and  bicarbonate  filtered  off  and  washed  with  50 
cc  of  alcohol  (98  per  cent).      The  alcohol  is  removed 
from  the  filtrate  and  washings  by  distillation,  and  the 
residue  boiled  with  100  cc  of  ammonium  chloride  solu- 

1  Goldschmiedt  and  Hemmelmayr,  M.  14,  210- 

2  Vohl  B.  10,  1807.     C.  Jehn,  Ibid.  10,  2108. 


60  RADICLES   IN   CARBON   COMPOUNDS. 

tion  (10  per  cent).  The  potassium  salt  of  the  acid  de- 
composes the  ammonium  chloride,  and  the  liberated 
ammonia  is  determined  in  the  usual  manner.  The 
amount  of  alkali  carbonate  dissolved  by  100  cc  of 
alcohol  (93  per  cent)  is  equivalent  to  0.34  cc  of  nor- 
mal acid ;  a  correction  for  this  must  be  applied  and  also 
one  for  the  ammonium  chloride  hydrolysed  by  the 
water;  this  is  determined  by  a  blank  experiment,  100 
cc  of  the  solution  being  boiled  during  the  same  length 
of  time,  1—2  hours,  as  in  the  actual  determination.1 

The  method  gives  good  results  with  the  feebler  fatty 
acids,  and  is  especially  useful  when  the  dark  color  of 
the  solution  prevents  direct  titration. 

(3)  Hydrogen  Sulphide  Method*  Compounds  con- 
taining carboxyl  liberate  hydrogen  sulphide  from  cer- 
tain metallo-hydrogen  sulphides  when  allowed  to  react 
in  an  atmosphere  of  hydrogen  sulphide,  according  to 
the  equation: 

NaSH  +  R.COOH  +  xH2S^->RCOONa- 
+  H2S  +  xH2S 

two  volumes  of  hydrogen  sulphide  being  liberated  for 
each  volume  of  hydrogen,  replaceable  by  metal,  in  the 
original  compound.  Hydroxyl  hydrogen  in  phenols, 
alcohols,  and  hydroxy-acids  does  not  react  with  the 
metallo-hydrogen  sulphides. 

Preparation  of  the  Solution. 

The  majority  of  alkali  salts  are  sparingly  soluble  in 
solutions  of  the  hydrosulphides ;  hence  the  solution  of 

1  F.  C.  Mcllhiney,  J.  Am.  16,  408. 

2  F.  Fuchs,  M.  9,  1142,  1153;  n,  363. 


METHOXYL,    ETHOXYL,    AND    CARBOXYL.          6l 

the  latter  must  not  be  so  concentrated  as  to  hinder  the 
reaction  from  being  rapidly  completed.  Potassium 
hydroxide  solution,  not  exceeding  10  per  cent,  is  boiled 
with  baryta  water  in  excess,  the  flask  closed,  and  the 
liquid  allowed  to  cool  and  deposit  barium  carbonate. 
The  clear  solution  is  now  poured  into  the  vessel  to  be 
used  for  the  analysis,  and  saturated  with  hydrogen 
sulphide. 

Method  of  Analysis. 

The  evolved  hydrogen  sulphide  may  be  determined : 

(a]  volumetrically  ; 

(b)  by  titration. 

The  former  method  is  the  easier,  and  is  therefore 
generally  employed. 

(a)    Volumetric  Determination. 

This  method  is  based  on  the  same  principle  as  Victor 
Meyer's  vapor  density  determination.  The  apparatus, 
Fig.  9,  consists  of  a  long-necked  flask  A,  made  of  thick 
glass;  it  is  fitted  with  a  rubber  stopper  c  through 
which  the  delivery  tube  B  passes,  this  is  wide  at  one 
end  but  terminates  in  a  capillary  at  the  other.  The 
second  hole  of  the  stopper  is  closed  by  means  of  a 
glass  rod  from  which  the  vessel  containing  the  sub- 
stance is  suspended.  Previous  to  the  determination 
the  greater  portion  of  the  flask  is  filled  with  hydro- 
gen sulphide,  but  the  upper  portion  of  the  neck  and 
the  delivery  tube  contain  air  which  is  expelled  by  the 
evolved  hydrogen  sulphide  and  collected  over  water 
in  a  graduated  tube.  The  substance  under  examina- 


62 


RADICLES   IN    CARBON   COMPOUNDS. 


tion  is    dried,   finely  powdered,    and    about    0.5    gram 

weighed  into  the 
small  vessel,  the 
glass  rod  being 
pressed  into  the 
rubber  stopper  as 
far  as  the  mark  i, 
the  vessel  fitted 
en  to  it  by  means 
of  the  stopper, 
which,  with  the 
delivery  tube,  is 
pressed  air-tight 
into  the  flask. 
The  apparatus  is 


I'lG    9. 


allowed    to    re- 


main for  a  few  moments  to  equalize  the  temperature, 
then  the  capillary  end  of  the  delivery- tube  is  dipped 
into  water  below  the  open  end  of  the  gas-measuring 
vessel,  and  the  vessel  with  the  substance  dropped  into 
the  sulphide  solution  by  pushing  in  the  rod  to  the 
mark  2,  care  being  taken  not  to  alter  the  position  of 
the  stopper  itself.  The  evolution  of  hydrogen  sulphide 
ceases  after  a  few  minutes.  The  same  solution  may 
be  employed  for  a  second  or  third  determination,  but 
each  time  the  delivery-tube  must  be  previously  filled 
with  dry  air.  The  weight  of  carboxyl  hydrogen  G  is 
calculated  from  the  results  by  the  formula: 

G  =  iV(f,-W) 

ss  ,.0.0000896 
760(1  +  0.00366/) 

V.(b  —  w).  0.00000005  895 
I  -f  0.00366^ 


METHOXYL,    ETHOXYL,    AND   CARBOXYL. 


FIG.  10. 


where  V  =  the  observed  volume  of  air  displaced  in 
cc,  b  =  the  height  of  the  barometer,  and  2x>the  tension 
of  aqueous  vapor  at  the  observed  temperature  /. 

(&)    Tit  ration  Method. 

The  apparatus  employed  consists  of  a  short-necked 
flask  A,  Fig.  10,  fitted  with  a  rubber  stopper  and  glass 
rod  exactly  as  used  in  the 
preceding  method,  but  the 
delivery-tube  is  short  in  order 
to  expedite  the  expulsion  of 
air.  Before  the  stopper,  with 
the  substance  adjusted  in  the 
manner  described  above,  is  in- 
serted into  the  flask,  tartaric 
acid  or  oxalic  acid  (about  0.25  gram)  is  dropped  into 
the  potassium  hydrogen  sulphide  solution  and  the  stop- 
per immediately  inserted  air-tight  as  shown.  As  soon 
as  the  evolution  of  gas  ceases  the  beaker  represented  in 
the  figure  is  replaced  by  a  smaller  one  containing  con- 
centrated potassium  hydroxide  solution.  Some  of  this 
rises  in  the  tube  on  account  of  the  absorption  of  the 
gas,  but  the  error  so  introduced  compensates  itself  at 
the  end  of  the  experiment.  As  soon  as  the  beaker  of 
alkali  has  been  put  into  position,  the  substance  is 
dropped  into  the  sulphide  solution  with  the  same  pre- 
cautions as  observed  in  the  preceding  method;  after 
the  cession  of  the  gas  evolution,  which  continues  dur- 
ing !~5  minutes,  the  pressure  is  adjusted  by  lowering 
the  beaker,  the  contents  are  poured  into  a  large  flask, 
and  the  beaker  and  evolution  tube  washed.  The  alkali 
and  washings  are  diluted  to  about  500  cc,  neutralized 


» 
64  RADICLES    IN   CARBON    COMPOUNDS. 

with  acetic  acid,  and  titrated  with  iodine  solution  in 
presence  of  starch.  Since 

H  ==  H2S  =  I2, 

the  iodine  required,  divided  by  2  X  126.5,  gives  the 
weight  of  the  replaceable  hydrogen.  The  error  due 
to  the  insertion  of  the  glass  rod  from  mark  I  to  2  may 
be  determined  by  means  of  a  blank  experiment,  but 
it  is  so  small  as  to  be  usually  negligible.  More  re- 
cently the  action  of  substituted  phenols,  etc.,  on  alkali 
hydrogen  sulphides  has  been  investigated1  with  the 
following  results: 

(1)  Haloid  substituted  phenols  with   one    hydroxyl 
group  are  without  action  on  the  sulphides,  but  if  two 
hydroxyl  groups  are  present  one  reacts. 

(2)  Only  the  paraminonitro-phenols  react. 

(3)  Under  certain  conditions    the    presence   of  car- 
boxyl  groups  causes  the  phenolic  hydroxyl  to  decom- 
pose the  sulphides. 

(4)  In  general   lactones  do  not  react,   but  lactone- 
acids  may  suffer  partial  resolution.2 

With  the  above  exceptions  the  method  provides  a 
ready  means  of  differentiating  carboxylic  hydrogen 
from  phenolic  or  alcoholic,  a  distinction  which  the  two 
preceding  methods  do  not  furnish  with  certainty. 

(4)  Iodine-oxygen    MetJwd?     This  depends  on    the 
fact  that  even  feeble  organic  acids  liberate  iodine  from 
potassium  iodide  and   potassium  iodate  in  accordance 
with  the  equation: 
6R.COOH+5KI+KIO3->6R.COOK  +  3 


1  Fuchs,  M.  II,  363  2  H.  Meyer.  Ibid.  19,  715. 

3  Baumann  and  Kux,  Z.  Anal.  Ch.  32,  129. 


METHOXYL,    ETHOXYL,    AND   CARBOXYL.          6$ 

The  liberated  iodine,  in  presence  of  alkali,  evolves 
oxygen  from  hydrogen  peroxide: 

I2+2KOH-->KOI  +  KI+H2O  and 
KOI+H202-»KI+H20+02. 

The  oxygen  may  be  measured  in  a  modified  Wagner 
and  Knop's  azotometer,1  or  in  any  other  convenient 
vessel. 

The  apparatus  consists  of  an  evolution  flask,  with  a 
small  cylinder  of  about  2O  cc  capacity  fused  to  the 
middle  of  the  bottom  inside,  and  a  large  glass  cylinder 
with  two  communicating  burettes  and  a  thermometer, 
fastened  to  the  interior  of  the  cover.  The  cylinder  and 
burettes  are  filled  with  water,  the  latter  by  connecting 
them  with  a  flask  from  which  water  is  forced  by  air 
pressure  from  a  hand  blower,  the  connecting  tube  being 
provided,  if  needful,  with  a  stop-cock.  The  evolution 
flask  is  closed  by  means  of  a  rubber  stopper  carrying 
a  tube  with  a  stop-cock  which  is  connected  with  the 
graduated  burette  below  the  stop-cock  in  which  the 
latter  terminates,  and  which  is  used  for  adjusting  the 
pressure.  The  temperature  of  the  evolution  flask  is 
equalized,  before  and  after  the  determination,  by  placing 
it  in  water  of  the  same  temperature  as  that  in  the  large 
cylinder  enclosing  the  burettes.  The  following  rea- 
gents are  required : 

(1)  Potassium  iodide  )  .     f       .  .  , 
,   .                       -it  absolutely  free  from  acid. 

(2)  lodate  ) 

(3)  Hydrogen  peroxide  2—3  per  cent  solution. 

(4)  Aqueous  potassium  hydroxide  solution  (i   :  i). 

(5)  Distilled   water,  recently  boiled  and  free  from 

carbonic  anhydride. 


Z.  Anal.  Ch.  13,  389. 


66  RADICLES    IN   CARBON   COMPOUNDS. 

The  determination  is  carried  out  in  the  following 
manner:  The  acid  (0.1-0.2  gram)  is  mixed  with  finely 
divided  potassium  iodate  (about  0.2  gram),  potassium 
iodide  (2  grams),  and  water  (40  cc)  in  a  bottle  provided 
with  a  well-fitting  stopper,  and  allowed  to  remain  at 
the  ordinary  temperature  during  twelve  hours,  or  at 
7O°-8o°  during  a  half  hour,  until  the  iodine  is  com- 
pletely precipitated.  The  solution  is  now  transferred  to 
the  outer  portion  of  the  evolution  flask,  the  bottle  being 
washed  with  not  more  than  10  cc  of  water.  Into  the 
inner  cylinder  of  the  evolution  flask  is  poured,  by 
means  of  a  funnel,  a  mixture  consisting  of  hydrogen 
peroxide  (2  cc)  and  potash  solution  (4  cc),  made  im- 
mediately before  use,  and  cooled  to  the  ordinary  tem- 
perature. The  evolution  flask  is  now  closed  with  its 
stopper  and  allowed  to  stand  in  water  during  ten  min- 
utes, the  stopcock  of  the  burette  being  opened  to  equal- 
ize the  pressure;  at  the  end  of  this  time  it  is  closed, 
the  level  adjusted  to  the  zero  mark,  and  if,  after  five 
minutes,  no  change  takes  place  the  experiment  is  pro- 
ceeded with,  otherwise  the  cooling  is  continued  during 
another  five  minutes.  When  equilibrium  is  established 
30-40  cc  of  water  are  run  from  the  burette  in  order  to 
reduce  the  pressure,  the  evolution  flask  is  removed  from 
the  cooling  vessel  by  means  of  a  cloth  and  rotated  so 
that  the  liquids  at  first  circulate  without  mixing  and 
are  then  suddenly  brought  into  contact.  The  shaking 
is  continued  vigorously  for  a  short  time  and  the  flask 
then  returned  to  the  cooling  vessel.  The  evolution  of 
oxygen  begins  at  once,  and  is  completed  in  a  few  sec- 

1  Baumann,  Z.  f.  ang.  Ch.  1891,  p.  328. 


METHOXYL,    ETHOXYL,    AND    CARBOXYL.          6/ 

onds;  after  about  ten  minutes  the  pressure  in  the  two 
burettes  is  adjusted  and  the  volume  read;  the  number 
of  cc  of  gas,  multiplied  by  the  value  in  the  table1  in  the 
appendix  corresponding  to  the  pressure  and  tempera- 
ture, gives  directly  the  weight  of  carboxylic  hydrogen. 
An  lodometric  method  for  the  determination  of  acids 
has  also  been  described;  for  details,  the  original  paper 
should  be  consulted.1 

METHODS    FOR   THE    SEPARATION  OF  ACIDS  are 
described  on  p.   160. 

1  M.  Groger,  Ibid.,  1890,  pp.  353,   385. 


CHAPTER   III. 

DETERMINATION   OF   CARBONYL  (CO), 

The  presence  of  the  carbonyl  group  in  aldehydes, 
ketones,  etc.,  is  recognized  by  the  preparation  of  de- 
rivatives of  the  following  compounds: 

(1)  Phenylhydrazine  and  its  substitution  products; 

(2)  Hydroxylamine ; 

(3)  Semicarbazine ; 
(4),  Thiosemicarbazine ; 

(5)  Semioxamazine; 

(6)  Aminoguanidine ; 

(7)  Paraminodimethylaniline; 

(8)  Barium   salts  of  aromatic  aminocarboxylic  or 

aminosulphonic  acids; 

(9)  Miscellaneous  derivatives. 

(l)    CARBONYL    DETERMINATION    BY    MEANS   OF 
PHENYLHYDRAZINE. 

The  method  is  divisible  as  follows: 

(A  )  Preparation  of  phenylhydrazones  from  phenyl- 

hydrazine. 
(B]  Preparation  of  substituted  hydr ozones. 

(Q  Indirect  Method. 

68 


DETERMINATION  OF  CARBONYL.        69 

(A)  Preparation  of  Phenylhydrazones.1 

Carbonyl  compounds  combine  with  phenylhydrazine 
forming  water  and  phenylhydrazones, 

C6H5NH.N:CRR,; 

diphenylhydrazones,  with  the  hydrazine  groups  linked 
to  neighboring  carbon  atoms,  are  termed  osazones. 
The  reaction  usually  takes  place  most  readily  in  dilute 
acetic  acid  solution,  often  at  the  ordinary  temperature, 
almost  always  by  heating  on  the  water-bath.  Fre- 
quently it  is  advisable  to  allow  the  reaction  to  proceed 
at  the  ordinary  temperature  in  presence  of  concentrated 
acetic  acid,  which  acts  as  a  dehydrating  agent  and  in 
which  the  phenylhydrazones,  as  a  class,  are  sparingly 
soluble.2  E.  Fischer  dissolves  or  suspends  the  sub- 
stance in  water  or  alcohol,  and  adds,  in  excess,  a  mix- 
ture of  phenylhydrazine  hydrochloride  (i  part)  and 
crystallized  sodium  acetate  (1.5  parts)  dissolved  in 
water  (8-10  parts).  Free  mineral  acids  must  be  neu- 
tralized by  means  of  sodium  hydroxide  or  sodium  car- 
bonate, as  their  presence  hinders  the  reaction ;  the 
presence  of  nitrous  acid  is  particularly  hurtful  and  it 
must  be  removed  by  means  of  carbamide,  as  otherwise 
it  reacts  with  the  phenylhydrazine  and  forms  diazoben- 
zene  imide  and  other  oily  products.  Confusion  may 
also  be  caused  by  the  production  of  acetylphenylhydra- 
zine  from  the  dilute  acetic  acid.3 

The  phenylhydrazones  gradually  separate  from  the 
solution  of  their  components  in  an  oily  or  crystalline 

1  E.  Fischer,  B.  16,  661,  2241,  foot-note;  17,  572;  22,  90;  41,  74. 

2  Overton,  B.  26,  20.  3  Anderlini,  Ibid.  24,  1993,  foot-note. 


70  RADICLES    IN    CARBON    COMPOUNDS. 

form,  and,  in  the  latter  case,  are  purified  by  recrystal- 
lization  from  water,  alcohol,  or  benzene. 

It  is  often  desirable  to  heat  the  compound  under  in- 
vestigation with  free  phenylhydrazine,  and  increased 
pressure  may  be  used  if  there  is  nx>  danger  of  phenyl- 
hydrazides  being  formed.1  The  product  is  poured  into 
water,  the  phenylhydrazone  removed  by  filtration, 
washed  with  dilute  hydrochloric  acid  to  free  it  from 
excess  of  phenylhydrazine,  and  recrystallized ;  in  some 
cases  glycerol  is  employed  for  washing,  the  last  por- 
tions of  it  being  removed  by  water.3  Aliphatic  ketones 
react  readily  in  ethereal  solution,  and  the  water  which 
is  produced  may  be  absorbed  by  recently  ignited  po- 
tassium carbonate  or  calcium  chloride.  In  the  case  of 
ketophenols  or  ketoalcohols  the  hydroxyl  group  should 
be  acetylated  before  treatment  with  phenylhydrazine; 
acids  are  usually  used  in  the  form  of  esters,  but  the 
sodium  salt  is  sometimes  employed3;  the  condensa- 
tion is  occasionally  promoted  by  the  addition  of  a  min- 
eral acid.4  Hydrazones  may  also  be  prepared  from 
oximes.5  The  carbonyl  group  in  many  lactones  and 
acid  anhydrides,  although  it  does  not  react  with 
hydroxylamine,  yields  phenylhydrazides  (additive  com- 
pounds), or,  at  high  temperatures,  condensation  pro- 
ducts. Hydrazine  also  yields  additive  compounds 
with  some  aromatic  lactones.6  Hydroquinonetetracar- 

1  M.  14,  395.  2  Thorns,  B.  29,  2988. 

3  Bamberger,  Ibid.  19,  1430.  4  Elbers,  Ann.  227,  353. 

5  Just,  B.  19,  1205.     v.  Pechmann,  Ibid.  20,  2543,  foot-note. 

6  W.  Wislicenus,  Ibid.  20  (1887),  401.     E.  Fischer  and  F.  Passmore, 
Ibid.  22  (1899),  2733.     L.  Gattermann  and  R.  Ganzert,  Ibid.  32  (1899), 
IJ33-     J-  Wedel,  Ibid.  33  (1900),   1766.     R.  Meyer  and  E.  Saul,  Ibid. 
26  (1893),  1271.     Ephraim,  Ibid.  26,  1376.     v.  Meyer  and  Miinchmeyer, 


DETERMINATION  OF  CARBONYL.        /I 

boxylic  anhydride  forms  a  compound  with  phenyl- 
hydrazine,  which  is  not  a  hydrazide  but  is  similar  to 
the  corresponding  derivative  of  phthalic  anhydride.1 
Many  quinones,  such  as  anthraquinone,  do  not  react 
with  phenylhydrazine  or  only  with  one  molecular  pro- 
portion, as  in  the  case  of  naphthoquinone  and  phenan- 
thraquinone,  whilst  some,  such  as  benzoquinone  and 
toluquinone,  oxidize  it  to  benzene.2  Ortho-disubsti- 
tuted  ketones  frequently  do  not  react  with  phenyl- 
hydrazine,3 and  certain  unsaturated  ketoalcohols,  such 
as  ethylic  acetoacetate  4  and  ethylic  camphoroxalate,5 
yield  monophenylhydrazides,  the  ketonic  group  being 
unaffected.  Hydroxyketones  and  aldehydes  of  the 
aliphatic  series  yield  phenylosazones,  a  portion  of  the 
phenylhydrazine  being  simultaneously  reduced  to  ani- 
line and  ammonia.6 

Osazones  are  often  most  readily  purified  by  solution 
in  pyridine,  or  a  mixture  of  pyridine  and  one  of  the 
ordinary  solvents.  As  there  is  a  great  tendency  for 
the  pure  pyridine  to  form  supersaturated  solutions  it  is 
often  convenient  to  precipitate  the  osazone  from  con- 
centrated solution  in  pyridine  by  the  addition  of  a  neu- 
tral solvent.  The  solubility  of  the  osazones  in  pyridme 
is  almost  the  same  as  that  of  the  parent  carbohydrate.7 

Ibid.  19  (1886),  1706,  2132.  Hemmelmayr,  M.  13,  669;  14,  398. 
Holle,  J.  pr.  33,  99. 

1  J.  U.  Nef,   Ann.  258  (1890),  283.  2  S.  p.  538. 

3  Baum,  B.  28,  3209.     v.  Meyer,  Ibid.  29,  830,  836. 

4  J.  U.  Nef,  Ann.  266,  52. 

5  Bishop   Tingle,  Am.  Chem.  Journ.  20,  339.     A.  Tingle  and  Bishop 
Tingle,  Ibid.  21,  258. 

8  E.  Fischer  and  Tafel,  B.  20,  3386. 
7  C.  Neuberg,  Ibid.  32  (1899),  3384. 


72  RADICLES    IN   CARBON   COMPOUNDS. 

Aliphatic  aldehydes  react  quite  rapidly  with  phenyl- 
hydrazine  hydrochloride.  Aliphatic  ketones  behave  in 
the  same  manner  towards  the  acetate,  but  react  slowly, 
or  not  at  all, with  the  hydrochloride.  On  this  fact  a 
method  for  their  separation  has  been  based.  (Cf.  p.  84). l 

A  method  has  been  described  for  the  purification  of 
commercial  phenylhydrazine.2  Vide  also  page  161. 

(B)  Preparation  of  Substituted  Hydrazones. 

The  chief  substitution  product  of  phenylhydrazine 
which  has  hitherto  been  employed  for  the  preparation 
of  phenylhydrazones  is  the  parabromo-derivative. 

Preparation  of  Parabromophenylhydrazine*  Phenyl- 
hydrazine (20  grams)  is  poured  into  hydrochloric  acid 
(2OO  grams,  sp.  gr.  =1x1.19)  and  the  precipitated  salt 
uniformly  distributed  throughout  the  liquid,  which  is 
cooled  to  o°;  bromine  (22.5  grams)  is  now  dropped 
in,  the  addition  occupying  10-15  minutes,  the  liquid 
being  well  shaken  during  this  time.  After  remaining 
during  twenty-four  hours  the  precipitate  is  removed, 
washed  with  a  little  cold  hydrochloric  acid,  dissolved 
in  water,  and  treated  with  sodium  hydroxide  in  excess. 
The  base  separates  in  flocculent  crystals  which  are  ex- 
tracted with  ether,  the  ether  evaporated,  and  the  resi- 
due recrystallized  from  water.  The  hydrochloric  acid 
mother  liquor  contains  bromodiazobenzene  chloride, 
which  is  reduced  by  the  addition  of  stannous  chloride 
(60  grams);  the  precipitate  is  separated,  washed  with 
concentrated  hydrochloric  acid,  and  treated  with  water 
and  alkali,  the  base  being  collected  and  purified  in  the 

1  A.  Michael,  J.  pr.  45  [2],  588. 

2  B.  Overton,  B.  26,  19;   E.  Fischer,  Ibid.  41,  74. 
8  Michaelis,  Ibid.  26,  2190. 


DETERMINATION  OF  CARBONYL.        73 

manner  described  above.  The  yield  is  80  per  cent. 
Bromophenylhydrazine  requires  to  be  protected  from 
light  and  air;  it  should  be  kept  in  the  dark  in  well- 
stoppered  colored  bottles  from  which  the  air  has  been 
displaced  by  carbonic  anhydride  or  coal-gas.  In  these 
circumstances,  if  the  compound  has  been  highly  puri- 
fied and  dried,  it  may  be  retained  for  years  without 
change ;  colored  specimens  may  be  readily  purified  by 
recrystallization  from  water,  to  which  a  few  drops  of 
sodium  hydroxide  should  be  added.  The  pure  com- 
pound melts  at  1 07 °- 1 09°,  the  acetyl  derivative  at  1 70° . l 

Substituted  Phenylhydrazones . 

Parabromophenylhydrazine  is  well  adapted  for  the 
identification  of  certain  sugars,  such  as  arabinose,2  and 
has  also  been  used  in  the  investigation  of  ionone  and 
irone ; 3  it  is  generally  employed  in  acetic  acid  solution, 
care  being  taken  to  prevent  the  liquid  from  boiling, 
as,  in  these  circumstances,  acetyl  parabromophenyl- 
hydrazine  is  formed.4 

Paranitrophenylhydrazine,  prepared  from  parani- 
traniline  by  means  of  the  diazo-reaction  also  gives  well 
defined  condensation  products  with  many  aldehydes  and 
ketones  which  serve  for  their  identification  better  than 
the  parabromophenylhydrazones  and  semicarbazones. 
The  reaction  usually  proceeds  in  aqueous  solution  with 
the  hydrochloride,  but  the  free  base  in  alcohol  or  acetic 
acid  may  be  employed.5 

1  Tiemann  and  Kriiger.  2  E.  Fischer,  B.  24,  4221,  foot-note. 

3  Tiemann  and  Kruger,  Ibid.  28,  1755.  4  Ibid.  26,  2199. 

5  E.  Bamberger  &  Kraus,  Ibid.  29(1896),  1834.  Bamberger,  Ibid.  32 
(1899),  1806.  E.  Hyde,  Ibid.  32,  1810;  F.  First,  Ibid.  33  (1900),  2098. 


74  RADICLES   IN   CARBON   COMPOUNDS. 

f}-Naphthylhydrasine?  which,  like  the  a  -deriva- 
tive, decomposes  on  exposure  to  light,  especially  in 
presence  of  moisture,  benzylphenylhydrazine?  and 
methylphenylhydrdzine*  are  all  well  adapted  for  the 
separation  and  identification  of  sugars.  Methylphenyl- 
hydrazine  only  yields  osazones  with  the  ketoses.  Oily 
phenylhydrazones  of  keto-bases  sometimes  yield  crys- 
talline salts.4 

In  addition  the  following  substituted  phenylhydra- 
zines  have  been  used  for  the  production  of  phenyl- 
hydrazones: dibromo-,  symmetrical  tribromo->  tetra- 
bromo-,  paracJiloro-,  pariodo-,  and  metadiiodo- ?  whilst 
some  derivatives  of  diphenylhydrazine  have  also  been 
described.6  Vide  also  p.  161. 

(C)  Indirect  Method.7 

This  method  depends  on  allowing  the  aldehyde  or 
ketone  to  react  with  excess  of  phenylhydrazine;  the 
excess,  together  with  any  hydrazide,  is  then  oxidized 
by  means  of  boiling  Fehling's  solution,  the  liberated 
nitrogen  being  collected;  phenylhydrazones  are  not 
decomposed  by  this  treatment. 

The  reagents  required  are  as  follows: 

Fehling' s  solution  made  by  mixing  equal  volumes  of 

1  A.  Hilger  and  S.  Rothenfusser,  B.  35  (1902),  1841. 

2  L.  de  Bruyn  and  A.  van  Ekenstein  Rec.   15,  97,  227.     O.  Ruff  and 
G.  Ollendorff,  B.  32(1899),  3234. 

3  C.  Neuberg,  Ibid.  35  (1902),  2626. 

4  M.  Scholz,  Ibid.  30  (1897),  2298. 

5  A.  Neufeld,  Ann.  248,  93. 

6  R.  Overton,  B.  26,  10;  C.  Neuberg,  Ibid.  33  (1900),  2245. 

1  H.  Strache,  M.  12,  514;  13,  299,  Benedikt  and  Strache,  Ibid.  14, 
270- 


DETERMINATION  OF  CARBONYL.        75 

copper  sulphate  solution  (70  grams  CuSO4. 5H2O  in  I 
liter  of  water)  and  alkaline  solution  of  sodium  potassium 
tartrate  (350  grams  of  the  tartrate,  and  260  grams 
potassium  hydroxide  in  I  liter  of  water). 

Sodium  acetate  (10  per  cent  solution). 

Phenylhydrazine  hydrochloride  (5  per  cent  solution.) 
The  analysis  is  made  by  mixing  the  compound  under 
examination  (0.1—0.5  gram)  with  an 'accurately  meas- 
ured quantity  of  the  phenylhydrazine  hydrochloride 
solution  (i  part)  and  the  sodium  acetate  solution  (ii 
parts)  in  a  100  cc  measuring  flask.  The  phenylhydra- 
zine hydrochloride  is  taken,  if  possible,  in  quantity 
sufficient  to  yield  15-30  cc  nitrogen.  Water  is  now 
added  to  the  mixture  in  the  flask  so  as  to  make  the 
volume  about  50  cc,  and  the  liquid  is  heated  on  the 
water-bath  during  15-30  minutes;  it  is  then  cooled, 
diluted  to  the  mark,  well  shaken,  50  cc  transferred  to 
the  dropping  funnel  T,  Fig.  II,  and  the  determination 


I  \C 

FIG.  11. 

conducted  in  the  manner  described  below.  The  flask 
A  has  a  capacity  of  750-1000  cc,  and  contains  200  cc 
of  Fehling's  solution,  which  is  boiled  while  a  rapid 


?6  RADICLES    IN   CARBON   COMPOUNDS. 

current  of  steam  is  blown  in  from  the  flask  B.  The 
tubes  D  and  R  must  be  flush  with  the  rubber  stoppers 
so  as  to  promote  the  removal  of  air.  The  tube  R  is  in 
two  pieces,  joined  by  the  rubber  tube  K;  its  lower  end 
is  covered  writh  a  piece  of  rubber  tube  £,and  dips  be- 
low water  in  the  dish  IV.  The  current  of  steam  is  con- 
tinued until  the  bubbles  of  gas  collected  are  very  small; 
it  is  impossible,  in  a  reasonable  time,  to  remove  all  the 
air  and  a  blank  determination  of  the  phenylhydrazine 
hydrochloride  solution  is  made,  previous  to  the  actual 
determination,  so  as  to  allow  for  this  error.  A  gram 
of  the  salt  eliminates  about  155  cc  nitrogen,  therefore, 
for  the  blank,  10  cc  of  the  solution  is  accurately  meas- 
ured out,  mixed  with  the  needful  proportion  of  sodium 
acetate  solution,  diluted  to  100  cc,  and  50  cc  trans- 
ferred to  the  dropping  funnel ;  the  end  of  this  is  drawn 
out  at  5"  and  cut  off  at  an  angle  so  as  to  avoid  the  col- 
lection of  bubbles  of  gas ;  before  the  funnel  is  fixed  in 
place  the  stem  is  filled  with  water.  When  the  greater 
portion  of  the  air  has  been  removed  from  the  apparatus 
in  the  manner  described  above,  the  phenylhydrazine 
salt  is  allowed  to  mix  with  the  Fehling's  solution,  care 
being  taken  to  prevent  the  water  flowing  from  W  into 
A.  When  all  has  been  added  the  funnel  is  washed 
out  twice  with  hot  water,  which  also  is  allowed  to  run 
into  A.  If  the  boiling  is  sufficiently  brisk  the  evolu- 
tion of  nitrogen  is  completed  in  2-3  minutes.  As 
soon  as  the  bubbles  are  as  small  as  those  of  the  air  at 
the  commencement  of  the  experiment  the  heating  is 
stopped,  the  hot  water  in  W  replaced  by  cold,  the  ex- 
cess escaping  into  the  dish  C  and  the  measuring  tube 
removed  to  a  cylinder  of  cold  water.  The  actual  de- 


DETERMINATION    OF   CARBONYL.  77 

termination  is  made  immediately  after  the  completion 
of  the  blank  experiment  and,  if  necessary,  repeated  a 
second  or  third  time;  since  200  cc  Fehling's  solution 
readily  liberates  150  cc  nitrogen,  the  quantity  taken  in 
A  amply  suffices  for  three  or  four  carbonyl  determina- 
tions. 

As  benzene  is  produced  during  the  oxidation  of  the 
phenylhydrazine,  a  drop  of  it  will  be  found  floating 
on  the  surface  of  the  water  inside  the  measuring  tube ; 
this  may  be  allowed  for  in  measuring  the  gas  or  it  may 
be  removed.  In  the  former  case  a  little  more  benzene 
is  introduced  into  the  tube  by  means  of  a  bent  pipette, 
and,  after  remaining  during  a  short  time,  the  volume 
of  nitrogen  is  read  off  in  the  ordinary  manner;  its 
reduction  to  o°  and  760  mm  may  be  made  by  the 
help  of  the  following  table,  the  values  in  the  second 
column  being  subtracted  from  the  observed  height  of 
the  barometer: 

Temperature.  Tension  of  benzene  -f-  water. 

I5°C.  72.7  mm. 

16  76.8 

17  80.9 

18  85.2 

19  89.3 

20  93-7 

21  98.8 

22  103.9 

23  i OQ.  i 

24  II4.3 

25  II9.7 

The  values  given  above  are  in  part  obtained  by  in- 
terpolation from  Regnault's  results  and  are  therefore 


RADICLES   IN   CARBON   COMPOUNDS. 


subject  to  error;  for  this  reason,  and  on  account  of  the 
high  vapor  tension  of  benzene,  its  removal  is  advisable.1 
To  accomplish  this  alcohol  is  added  to 
the  tube  of  nitrogen,  which  is  placed  in 
a  cylinder  of  about  its  own  length  filled 
with  water  (Fig.  12).  A  glass  tube  5 
mm  in  diameter  is  bent  into  the  form 
of  a  U  as  shown  in  the  figure,  the 
smaller  limb  terminating  in  a  jet  and 
being  of  such  length  that,  when  the 
bent  portion  rests  on  the  bottom  of  the 
cylinder,  the  jet  is  several  cm  below 
the  surface  of  the  water.  The  longer 
limb  rises  about  40  cm  above  the  sur- 
face of  the  water  and  is  connected  at 
the  end  by  means  of  a  piece  of  thick 
walled  rubber  tube  with  a  dropping 
funnel.  The  U  tube  is  completely 
filled  with  water  and  placed  in  the  posi- 
tion shown  in  the  figure.  Alcohol 
(about  200  cc)  is  now  allowed  to  flow 
from  the  funnel  into  the  measuring  tube ; 

__  __    it  issues  from  the  jet  in  a  fine  stream 

FIG.  12.  ancj    absorbs    the  benzene  vapor  pres- 

ent in  the  nitrogen  as  well  as  that  floating  on  the 
water;  the  alcohol  is  removed  in  a  similar  manner  by 
washing  with  at  least  400  cc  of  water,  and  the  tube  of 
nitrogen  then  removed  to  another  cylinder  of  water, 
where,  after  a  suitable  interval,  the  volume  of  gas  is 
read.  The  amount  of  carbonylic  oxygen  O  is  ob- 


1  Benedikt  and  Strache,  M.  14,  373. 


DETERMINATION  OF  CARBONYL.        79 

tained  from  the  volume  of  nitrogen,  corrected  to  o° 
and  760  mm,  by  the  expression:  O  =  (g.  V.  —  2  F0.). 

15.96  100  _  0.07178 

0.0012562.^1^.  —  ^  -  O  =  (g.  V.  -  2  V0)—^fc, 

where  g  is  the  weight  of  phenylhydrazine  hydrochloride 
taken,  V  the  volume  of  nitrogen  evolved  by  I  gram  of 
this  salt,  5  the  weight  of  the  compound  employed,  and 
VQ  the  volume  of  nitrogen  obtained  at  /V.  T.P.  The 
theoretical  value  of  V  is  154.63  cc,  but  the  value  em- 
ployed in  the  calculation  is  that  obtained  in  the  blank 
experiment. 

If  the  phsnylhydrazone  is  insoluble  in  water  or  dilute 
alcohol,  or  if  sparingly  soluble  phenylhydrazides  are 
formed,  the  preparation  of  the  phenylhydrazone  must 
be  made  in  alcoholic  solution;  in  this  case  the  weight 
of  the  column  of  liquid  in  the  funnel  T,  Fig.  11,  will 
not  be  sufficient  to  overcome  the  pressure  of  steam  in 
the  flask  A.  This  difficulty  may  be  surmounted  by 
fitting  the  open  end  of  the  funnel  with  a  rubber  stop- 
per, carrying  a  tube  and  stop-cock.  On  blowing 
through  the  tube  the  alcoholic  liquor  is  forced  into  the 
flask,  but  great  care  is  necessary,  as  the  sudden  evolu- 
tion of  alcoholic  vapor  may  eject  liquid  from  flask  A  to 
B,  or  may  even  lead  to  an  explosion.  A  second  ob- 
jection to  the  use  of  alcohol  is  that,  at  its  boiling- 
point,  ketones  do  not  always  react  quantitatively  with 
phenylhydrazine.  Both  difficulties  may  be  overcome 
by  the  use  of  recently  boiled  amylic  alcohol  as  solvent; 
the  portion  of  it  which  passes  over  with  the  nitrogen 
being  subsequently  removed,  simultaneously  with  the 
benzene,  by  washing  with  alcoh®!  and  water.  (Cf.  p. 


80  RADICLES    IN    CARBON    COMPOUNDS. 

(2)    PREPARATION    OF    OXIMES.1 

In  the  preparation  of  oximes  the  hydroxylamine  i  - 
employed  in  the  form  of  the  free  base,  the  hydrochlo- 
ride,  as  potassium  liydroxylamincsiilpJionate,  or  zinc 
dihydroxylamine  hydrochloride.  Aldoximcs  are  ob- 
tained by  treating  aldehydes  with  an  equimolecular 
proportion  of  hydroxylamine  hydrochloride  in  concen- 
trated aqueous  solution,  adding  sodium  carbonate  (0.5 
mol.),  and  allowing  the  mixture  to  remain  at  the 
ordinary  temperature  during  J-8  days.  The  oxime  is 
extracted  with  ether,  the  solution  dried  over  calcium 
chloride,  and,  after  the  removal  of  the  ether,  the  resi- 
due rectified.  An  aqueous-alcoholic  solution  is  used 
for  aldehydes  insoluble  in  water,  and  those  that  are 
readily  oxidizable,  such  as  benzaldehyde,  are  treated 
in  flasks  from  which  the  air  has  been  removed  by 
means  of  carbonic  anhydride.2  Oximes  of  the  car- 
bohydrates, which  are  so  readily  soluble  in  water  that 
they  cannot  be  separated  from  the  inorganic  salts  re- 
sulting from  the  use  of  hydroxylamine  hydrochloride 
and  sodium  carbonate  or  sodium  hydroxide,  are  treated 
with  the  calculated  quantity  of  free  hydroxylamine  in 
alcoholic  solution;  after  several  days  the  oxime  gradu- 
ally crystallizes  out.3  Alcoholic  solution  of  hydroxyl- 
amine is  prepared  by  intimately  mixing  the  hydro- 
chloride  with  the  necessary  quantity  of  potassium 
hydroxide  together  with  a  little  water,  and  then  adding 
absolute  alcohol;  the  clear  liquid  is  afterwards  sep- 

1  V.   Meyer  and  Janny,   B.    15,   1324,   1525.     Janny,  Ibid.    15,  2778; 
16,  170. 

2  Petraczek,  Ibid.  15,  2783.  3  VVohl.  Ibid.  24,  994.     S.,  p.  367. 


DETERMINATION    OF   CARBONYL.  8 1 

arated  from  the  precipitated  potassium  chloride.1  The 
solution  gradually  acquires  a  slight  yellow  color,2  which 
may  be  obviated  by  substituting  sodium  ethoxide  for 
the  potassium  hydroxide. 

Ketoximes  are  usually  formed  less  readily  than  the 
aldoximes;  for  their  preparation  the  ketone  is  mixed 
with  the  necessary  proportions  of  sodium  acetate  and 
hydroxylamine  hydrochloride  in  aqueous  or  alcoholic 
solution,  and  the  liquid  heated  on  the  water-bath  dur- 
ing 1-2  hours,  or  the  ketone,  in  alcoholic  solution, 
may  be  heated  in  a  sealed  tube  with  the  hydrochloride 
at  i6o°-i8o°  during  8-10  hours,3  but  sometimes,  in 
these  circumstances,  instead  of  the  oximes,  derivatives 
of  them  are  formed  by  intramolecular  rearrangement.4 
In  many  cases  it  is  highly  advantageous  to  allow  the 
carbonyl  derivative  and  the  hydroxylamine  to  react  in 
strongly  alkaline  solution ;  the  proportions  which 
usually  give  the  best  results  are  ketone,  in  alcoholic 
solution  (i  mol.),  hydroxylamine  hydrochloride  (1.5-2 
mol.),  alkaline  hydroxide  (4.5-6  mol.) ;  the  last  two  are 
dissolved  in  the  smallest  requisite  quantity  of  water.5 
The  reaction  is  often  completed  at  the  ordinary  tem- 
perature in  a  few  hours;  occasionally  heating  on  the 
water-bath  is  desirable.  This  method  cannot  of  course 
be  used  with  ketones  or  aldehydes  that  are  attacked  by 
alkali,  nor  in  the  preparation  of  dioximes  which  readily 
change  into  their  anhydrides  in  the  presence  of  alkali. 

1  Volhard,  Ann.  253,  206.  2  Tiemann,  B.  24,  994. 

3  Homolka,  Ibid.  19,  1084. 

*  K.   Auwers  and   F.   v.   Meyenburg,   Ibid.    24  (1891),   2386;   A.  W. 
Smith,  Ibid.  24,  4051;  F.  H.  Thorp,  Ibid.  26  (1893),  1261. 
5  Auwers,  Ibid.  22,  609. 


82  RADICLES    IN   CARBON    COMPOUNDS. 

In  such  cases  an  acid  liquid  may  be  employed.  Qui- 
none  furnishes  an  example  of  this.  In  alkaline  solu- 
tion it  is  reduced  by  hydroxylamine  to  hydroquinone, 
while  in  aqueous  solution,  in  presence  of  hydrochloric 
acid  and  hydroxylamine  hydrochloride,  a  dioxime  is 
formed.1  Some  compounds,  such  as  phenylglyoxalic 
acid,  yield  oximes  both  in  alkaline  and  acid  solutions.2 
Oximes  of  ketonic  acids  may  be  obtained  by  treating 
the  alkali  salt  in  neutral  aqueous  solution  with  hydroxy- 
lamine hydrochloride ;  the  precipitation  of  oxime  usually 
commmences  at  once,  especially  if  the  liquid  is 
warmed  .3  Sometimes  it  is  advisable  to  convert  the  acid 
into  its  methyl  ester  and  avoid  the  use  of  excess  of  hy- 
droxylamine hydrochloride  so  as  to  prevent  the  forma- 
tion of  nitriles.4  Oily  oximes  may  be  converted  into 
crystalline  acetic  acid  derivatives  R:  N.O.CH2.COOH 
by  heating  with  chloracetic  acid  (i  mol.),  and  potassium 
hydroxide  (2  moL),  in  alcoholic  solution.5 

Potassium  hydroxylamine  sulpJwnate,  supplied  by 
the  "  Badischen  Anilin-  und  Sodafabrik, "  under  the 
name  "  Reducirsalze,  "  has  been  employed,  in  aqueous- 
alcoholic  solution,  for  the  preparation  of  oximes;6  in 
presence  of  free  alkali  it  is  hydrolysed,  and  the  lib- 
erated hydroxylamine  acts,  in  the  nascent  state,  on  the 
carbonyl  compounds.7  It  also  possesses  the  advantage 
of  cheapness. 

1  Nietzki  and  Kehrmann,  B.  20,  614.  2  S.,  p.  370. 

3  Bamberger,  Ibid.  19,  1430. 

4  Garelli,  Gazz.  21,  2,  2173. 

5  F    Tiemann,  B    31  (1898),  872. 

6  Kostanecki,  Ibid,  22,  1344. 

7  Raschig,  Ann.  241,  187. 


DETERMINATION  OF  CARBONYL.        83 

Zinc  dihydroxylamine  hydrochloride,  ZnCl2.2NH2OH, 
has  been  used  chiefly  for  the  preparation  of  ketoximes1 
as  its  resolution  into  hydroxylamine  and  anhydrous  zinc 
chloride  facilitates  the  elimination  of  water.  It  is  pre- 
pared2 by  adding  zinc  oxide  (i  part)  to  hydroxylamine 
hydrochloride  (2  parts)  in  boiling  alcoholic  solution. 
The  boiling  is  continued  in  a  reflux  apparatus  for  a  few 
moments,  and  the  liquid  allowed  to  cool.  The  com- 
pound is  deposited  as  a  crystalline  powder  which  dis- 
solves sparingly  in  water  or  alcohol,  but  readily  in  solu- 
tions of  hydroxylamine  hydrochloride. 

Ortho-  and  paraquinones,  and  metadiketones  do  not 
react  with  hydroxylamine  if  several  atoms  of  hydro- 
gen in  the  ortho-position  are  replaced  by  haloid  atoms 

or  alkyl  groups.3     Aromatic    ketones    of  the   formula 

i      i 
(CH3.C)2C.COR,    where    R  =  phenyl    or    an     alcohol 

radicle,  are  also. incapable  of  forming  oximes;4  indeed, 
the  presence  of  carbonyl,  which  does  not  yield  oximes, 
in  such  compounds  as  acids,5  amides,6  or  esters7  may, 
by  the  production  of  hydroxamic  acids,  lead  to  errone- 
ous results.  The  statement  that  alkyl  salicylates  and 
hydroxylamine  give  salicylhydroxamic  acid7  has  been 
confirmed.8  The  unsaturated  ketoalcohol  camphor- 
oxalic  acid. 

C:C.OH.CO.OH 
C8H14<  i 

CO 

1  Crismer,  Bull.  soc.  chim.  [3],  3,  114.  2  B.  23,  R.  223. 

3  Kehrmann,  Ibid.  21,  3315       Herzig  and  Zeisel,  Ibid.  21,  3494.     Cf. 
Ibid  22,  1344- 

4  V.  Meyer,  Ibid.  29,  836.      Feit  and  Davies,  Ibid.  24,  3546,    Biginelli, 
Gazz.  24,  /,  437.     Glaus,  J.  pr.  45,  383.     Baum,  B.  28,  3209. 

5  Nef,  Ann.  258,  282.  6  C.  Hoffmann,  B.  22,  2854. 

7  Jeanrenaud,  Ibid.  22,  1273.    8  A.  Tingle,  Am.  Chem.  Journ.  24,  52. 


84  RADICLES    IN   CARBON    COMPOUNDS. 

yields  an  additive  compound 

CH.C.OH.CO.OH 
C8H14<  I 

CO  NH.OH 

with  hydroxylamine,1  and  it  has  been  subsequently 
shown  that  certain  unsaturated  ketones,  such  as  pho- 
rone,  behave  in  a  similar  manner.2  Vide  also  p.  163. 

(3)  PREPARATION  OF  SEMICARBAZONES.3 

The  formation  of  well-crystallized  derivatives  of 
semicarbazine  has  proved  extremely  useful  in  the  inves- 
tigation of  terpene  compounds  which  often  yield  liquid 
oximes,  and  phenylhydrazonesthat  only  crystallize  with 
difficulty  and  readily  undergo  decomposition.  As  a 
rule  the  aldehyde  or  ketone  combines  with  semi- 
carbazine in  equimolecular  proportion,  but  ethylic 
aldehydophenylcarbonate  yields  the  compound 

C2H5O.CO.O.C6H4.CH:N.NH.CO.N;CII.C6II4.O.CO.OC2H54 

Aliphatic  ketones  have  varying  velocities  of  interac- 
tion with  different  salts  of  semicarbazine,  hence, by  the 
successive  addition  of  different  semicarbazine  salts  to  a 
mixture  of  such  ketones,  a  separation  of  them  may  be 
effected  (cf.  p.  72). 5 

Preparation  of  Semicarbazine  Salts.6 

(A)   Semicarbazine  HydrocJiloride. 
NH2.CO.NH.NH2.HC1 

1  Bishop  Tingle,  Am.  Chem.  Journ.  19,  408. 

2  C.  Harries  and  F.  Lehmann,  B.  30,  231,  2726. 

3  Baeyer  and  Thiele,  Ibid.  27,  1918. 

*  H.  Cajar,  Ibid.  31  (1899),  2806. 

5  A.  Michael,  J.  pr.  60  [2]  (1899),  347. 

•  T.  Curtius  and  K.  Heidenrich,  Ibid.  52  [2]  (1895),  465. 


DETERMINATION  OF  CARBONYL.        85 

is  prepared  from 

(a)  Hydrazine  sulphate?- 

(b)  Nitrocarb amide? 

(a)  Hydrazine  sulphate  (13  grams)  is  dissolved  in 
water  (100  cc),  and  neutralized  with  dry  sodium  car- 
bonate (5. 5  grams);  when  cold,  potassium  cyanate  (8.8 
grams)  is  added,  and  the  solution  allowed  to  remain 
overnight.  A  small  quantity  of  hydrazodicarbonamide, 
NH2.CO.NH.NH.CO.NH2,  is  deposited  which  is  some- 
what augmented  on  acidifying  with  dilute  sulphuric 
acid.  The  amide  is  removed, and  the  acid  liquid  well 
shaken  with  benzaldehyde ;  the  precipitate  of  benzal- 
semicarbazone  which  forms  is  separated,  and  well 
washed  with  ether.  It  is  now  carefully  heated  on  the 
water-bath,  in  portions  of  20  grams,  with  concentrated 
hydrochloric  acid  (40  grams),  sufficient  water  being 
added  to  cause  the  hot  liquid  to  become  clear ;  the  benz- 
aldehyde is  removed  by  repeatedly  extracting  the  hot 
liquid  with  benzene;  when  cold  the  aqueous  solution 
deposits  small  needles  of  semicarbazine  hydrochloride, 
which  are  removed,  dried,  and  recrystallized  from  dilute 
alcohol.  The  purified  compound  forms  prisms  which 
decompose  at  1,73°.  The  mother-liquors  yield  a  further 
quantity  of  the  benzal  derivative  when  treated  with 
benzaldehyde.  In  place  of  benzaldehyde  acetone  may 
be  employed  to  separate  the  semicarbazine,  the  result- 
ing product  requires  24  hours  to  separate,  but  is  more 
easily  decomposed  than  the  benzal  derivative.  The 
mother-liquor  may  be  treated  with  benzaldehyde  or 

1  Thiele  and  O.  Stange,  B.  28,  32. 

2  Thiele  and  Heuser,  Ann.  288,  312. 


86  RADICLES    IN   CARBON   COMPOUNDS. 

exactly  neutralized,  evaporated  to  dryness,  and  the 
residue  extracted  with  acetone.  The  yield  is  60  per 
cent.1 

(ft)  Commercial  nitrocarbamide  (225  grams)  is  mixed 
with  concentrated  hydrochloric  acid  (1700  cc),  a  little 
ice  added,  and  the  liquid  made  into  a  paste  by  the  suc- 
cessive additions  of  small  quantities*  of  zinc-dust  and 
ice;  constant  stirring  is  necessary,  and  the  temperature 
must  not  exceed  o°.  The  operation  may  be  carried 
out  in  an  enamelled  dish  cooled  by  means  of  a  freezing 
mixture ;  when  it  is  completed  the  product  is  allowed 
to  remain  for  a  short  time,  the  excess  of  zinc-dust  re- 
moved, and  the  filtrate  saturated  with  sodium  chloride. 
Sodium  acetate  (200  grams)  is  now  added,  together 
with  acetone  (100  grams),  and  the  liquid  placed  on  ice 
or  in  a  freezing  mixture.  In  the  course  of  several  hours 
a  double  salt  of  zinc  chloride  and  acetone  semicarba- 
zone  crystallizes  out,  it  is  collected  and  washed,  first 
with  sodium  chloride  solution  and  finally  with  a  little 
water.  The  yield  is  40—55  per  cent.  The  zinc  com- 
pound (200  grams)  is  digested  with  concentrated  ammo- 
nium hydroxide  (350  cc),  and  after  some  time  the  liquid 
is  filtered ;  the  residue  consists  of  acetone  semicarba- 
zone,  which  is  converted  into  semicarbazine  salts  in 
the  manner  described  above  for  the  benzal  derivative. 
Many  ketones  do  not  readily  react  with  semicarbazine 
hydrochloride  and  the  products  obtained  from  some 
may  contain  chlorine ;  in  such  cases  semicarbazine  sul- 
phate should  be  employed. 

1  J.  Thiele  and  O.  Stange,  Ann.  283  (1894),  19. 


DETERMINATION   OF   CARBONYL.  8/ 

(B)  Preparation  of  Semicarbazine  Sulphate  1 

The  filtrate  from  hydrazodicarbonamide,  prepared  in 
the  manner  described  above,  is  cautiously  made  alka- 
line and  shaken  with  acetone;  the  acetone  semicarba- 
zone,  which  is  deposited,  is  mixed  with  alcohol,  and 
treated  with  the  calculated  quantity  of  sulphuric  acid; 
the  sulphate  crystallizes  out  and  is  purified  by  washing 
with  alcohol.  Vide  also  p.  164. 

Preparation  of  Semicarbazones? 

Semicarbazine  hydrochloride,  dissolved  in  the  mini- 
mum quantity  of  water,  is  mixed  with  the  calculated 
amount  of  potassium  acetate  in  alcoholic  solution,  and 
the  ketone  added,  together  with  water  and  alcohol 
sufficient  to  give  a  clear  homogeneous  liquid.  This  is 
allowed  to  remain  until  the  completion  of  the  reaction, 
which  is  recognized  by  the  deposition  of  crystals  when 
the  mixture  is  diluted  with  water,  and,  as  in  the  case 
of  hydroxylamine,  may  require  from  a  few  minutes  to 
four  or  five  days.  Sometimes  it  happens  that  the  de- 
posit produced  is  oily  and  only  solidifies  after  several 
hours.  The  use  of  Semicarbazine  sulphate  is  illustrated 
by  the  preparation  of  ionone  semicarbazone,  which 
cannot  be  obtained  from  the  hydrochloride.  The  sul- 
phate is  used  in  a  finely  divided  form  and  added  to 
glacial  acetic  acid,  in  which  the  equivalent  quantity  of 
sodium  acetate  has  been  dissolved;  after  remaining  at 
the  ordinary  temperature  during  twenty-four  hours  the 

1  Tiemann  and  Kruger,  B.  28,  1754. 

2  Baeyer,  Ibid.  27,  1918 


88  RADICLES    IN   CARBON    COMPOUNDS. 

solution  of  ionone  is  added,  and  the  liquid  allowed  to 
remain  three  days  longer.  The  product  is  poured  into 
a  considerable  volume  of  water,  extracted  with  ether, 
and  the  ether  freed  from  acetic  acid  by  treatment  with 
sodium  carbonate  solution.  After  drying  and  removal 
of  the  ether,  the  residue  is  treated  with  ligroin  to  re- 
move some  impurities,  and  the  remaining  product  crys- 
tallized from  a  mixture  of  benzene  and  ligroin.  In 
some  cases  the  ketone  is  dissolved  in  glacial  acetic 
acid,1  or  free  semicarbazine,  prepared  by  treating  a 
concentrated  aqueous  solution  of  the  hydrochloride 
with  absolute  alcoholic  sodium  ethoxide  solution,  is 
employed.2 

The  production  of  stereoisomeric  semicarbazones  of 
cyclic  ketones  has  been  investigated.3 

Should  a  ketone  not  yield  a  crystalline  semicarbazone 
it  is  advisable  to  convert  it  into  the  aminoguinadine 
picrate,  as  these  compounds  are  distinguished  by  the 
ease  with  which  they  crystallize.  (Cf.  pp.  92,  164). 

(4)    PREPARATION    OF    THIOSEMICARBAZINE 
DERIVATIVES.4 

Thiosemicarbazine,  NH2.CS.NH.NH2,  is  prepared 
by  gently  heating  commercial  hydrazine  sulphate  (50 
grams),  water  (200  cc)  and  calcined  potassium  carbonate 
(27  grams).  When  solution  has  taken  place  potassium 
thiocyanate  (40  grams)  is  added,  the  liquid  boiled  for  a 

1  F.  Tiemann,  B.  28  (1895),  2192. 

2  R.  Brener,  Ibid.  31  (1898),  2199. 

3  N.  Zelinsky,  Ibid.  30  (1897),  1541. 

4  M.  Freund  and  A.  Schander,  Ibid.  29  (1896),  2501. 


DETERMINATION  OF  CARBONYL.        89 

few  minutes,  alcohol  (200-300  cc)  is  added  to  precipi- 
tate potassium  sulphate,  and  the  filtrate  evaporated 
until  gas  evolution  begins.  The  product  is  treated 
with  water,  filtered,  and  the  filtrate  evaporated  as  be- 
fore. This  treatment  is  repeated  4-5  times.  The 
yield  of  crude  product  is  70  per  cent  of  the  theoretical. 

Thiosemicarbazine  readily  reacts  with  aldehydes  and 
ketones,  the  resulting  thiosemicarbazones  are  separated 
from  the  excess  of  reagent  by  solution  in  alcohol  or 
some  other  organic  solvent,  and  then  treated  with  an 
aqueous  or  alcoholic  solution  of  silver  nitrate.  The 
salt  formed  is  usually  curdy;  after  washing  and  drying 
it  is  dissolved  in  water  or  alcohol,  or  suspended  in 
ether  according  to  the  solubility  of  the  thiosemicarba- 
zone,  and  the  aldehyde  regenerated  by  treatment  with 
a  mineral  acid.  In  the  case  of  compounds  volatile  with 
steam  it  is  advantageous  to  use  phthalic  anhydride  in- 
stead of  the  mineral  acid.1 

The  method  is  very  generally  applicable,  and  has 
been  extremely  useful  in  separating  the  aldehydes 
formed  by  the  decomposition  of  gelatine.  It  cannot 
be  employed  for  the  purification  of  sugars  on  account 
of  the  solubility  of  the  silver  salts.  Copper  acetate, 
mercuric  acetate,  mercuric  cyanide,  and  potassium 
mercuric  iodide  may  be  substituted  for  the  silver 
nitrate ;  the  resulting  copper  salts  are  usually  amorph- 
ous, the  others  crystalline. 

1  C.  Neuberg  and  W.    Neumann,    B.  35  (1902),    2049.      M.   Freund 
and  A.  Schander,  Ibid.  2602. 


90  RADICLES    IN   CARBON   COMPOUNDS. 

(5)    PREPARATION    OF    SEMIOXAMAZINE 
NH^CO.CO.NH.NH.,.1 

Potassium  hydroxide  (9  grams)  is  dissolved  in  water 
(100  grams),  and  finely  divided  hydrazine  sulphate  (10 
grams)  added ;  the  liquid  is  diluted  with  its  own  vol- 
ume of  alcohol,  potassium  sulphate  removed,  and  the 
filtrate  warmed  on  the  water-bath  with  oxamethane 
until  solution  takes  place.  On  cooling  the  semioxama- 
zine  is  deposited,  and  is  purified  by  recrystallization 
from  water.  Semioxamazine  readily  yields  crystalline 
derivatives  with  aldehydes,  which,  unlike  many  semi- 
carbazine  derivatives,  only  occur  in  one  form,  but  its 
interaction  with  ketones  is  irregular. 

(6)  PREPARATION  OF  AMINOGUINADINE  DERIVATIVES.8 

Preparation  of  Aminoguinadine  Salts* 

Nitroguinadine  (208  grams)  is  mixed  with  zinc-dust 
(700  grams),  and  sufficient  ice  and  water  to  form  a  stiff 
paste;  to  this  commercial  glacial  acetic  acid  (124 
grams),  diluted  with  its  own  volume  of  water,  is  added, 
the  mixture  is  well  stirred,  and  great  care  taken  to  add 
ice  so  that  during  the  2-3  minutes  required  for  the 
addition  of  the  acid  the  temperature  shall  not  exceed 
o°.  The  temperature  is  now  allowed  to  rise  gradually 
to  40°;  at  this  stage  the  mixture  is  viscid  and  has  a 
yellow  color  due  to  an  intermediate  product.  The 
temperature  is  maintained  at  4O°-45°  until  a  little  of 
the  filtered  liquid  ceases  to  yield  a  red  color  with 

1  W.  Kerp  and  K.  Unger,  B.  30  (1897),  585. 

2  Baeyer,  Ibid.  27,  1919.  3  Thiele,  Ann.  270,  23. 


DETERMINATION  OF  CARBONYL.        91 

sodium  hydroxide  and  a  ferrous  salt.  The  conclusion 
of  the  operation  is  usually  indicated  by  evolution  of 
gas  and  the  formation  of  a  frothy  scum  on  the  surface 
of  the  liquid.  The  product  is  filtered,  the  residue  well 
washed  with  water,  the  washings  and  filtrate  mixed 
with  hydrochloric  acid  sufficient  to  liberate  the  acetic 
acid,  and  the  whole  concentrated  to  the  smallest  pos- 
sible bulk;  it  is  then  treated  with  alcohol,  again  evap- 
orated to  expel  water,  and  the  solid  boiled  out  with 
alcohol;  this,  when  cold,  deposits  aminoguinadine 
hydrochloride,  which  is  further  purified  by  recrystalli- 
zation  from  alcohol  to  which  animal  charcoal  has  been 
added.  The  pure  salt  melts  at  163°. 

Preparation  of  Aminoguinadine  Bicarbonate.1 

The  liquid  obtained  by  the  reduction  of  nitroguina- 
dine  with  zinc-dust  and  acetic  acid  is  maintained 
slightly  acid  with  acetic  acid,  evaporated  to  about  500 
cc,  cooled,  and  treated  with  concentrated  sodium  or 
potassium  bicarbonate  solution  to  which  a  little  am- 
monium chloride  has  been  added  to  prevent  the  de- 
position of  any  zinc.  The  aminoguinadine  salt  is 
completely  precipitated  in  twenty-four  hours;  it  is 
sparingly  soluble  in  hot  water  but  suffers  decomposi- 
tion, and  when  slowly  heated  it  melts  and  decomposes 
at  172°. 

The  nitrate,  and  the  normal  and  hydrogen  sulphates 
are  prepared  in  a  similar  manner. 

1  Thiele,  Ann.  302,  333. 
<A^^/?>v 

OF  THE  X 

UNIVERSITY    } 

OF  / 


92  RADICLES   IN   CARBON    COMPOUNDS. 

Preparation  of  Aminoguinadine  Pier  ate  Derivatives. 

Aminoguinadine  hydrochloride  is  dissolved  in  a 
small  quantity  of  water  containing  a  trace  of  hydro- 
chloric acid,  and  the  ketone  added,  together  with  suffi- 
cient alcohol  to  give  a  clear  solution.  The  reaction  is 
completed  by  boiling  for  a  short  time.  The  product  is 
treated  with  water  and  sodium  hydroxide  solution  in 
excess,  and  the  liquid  base  extracted  by  means  of 
ether.  The  ethereal  solution  is  separated,  the  ether 
removed,  the  residual  oil  suspended  in  water,  and 
treated  with  picric  acid  in  aqueous  solution,  the  picrate 
is  quickly  deposited  in  granular  crystals  which  are  puri- 
fied by  recrystallization  from  concentrated  or  dilute 
alcohol. 

Some  carbohydrate  derivatives  of  aminoguinadine 
are  known.1 

(7)    PREPARATION      OF     PARAMINODIMETHYLANILINE 
DERIVATIVES. 

Condensation  products  of  aldehydes  and  paraminodi- 
methylaniline  may  be  prepared  by  mixing  the  con- 
stituents, with  or  without  the  addition  of  alcohol.  The 
temperature  of  the  liquid  rises  spontaneously,  and  the 
condensation  product  usually  separates  in  crystals.2 

»  Wolff  and  Herzfeld,  Z.  Rub.  1895,  743.  Wolff,  B.  27,  971;  28, 
2613. 

2  A.  Cahn,  Ibid.  17,  2938.  The  literature  of  this  subject  is  given  in 
M.  and  J.  II,  p.  515. 


DETERMINATION    OF   CARBONYL.  93 

(8)    DERIVATIVES     OF     BARIUM    SALTS     OF    AROMATIC 
AMINOCARBOXYLIC    AND  AMINOSULPHONIC    ACIDS.1 

The  substance  (liquid),  containing-  an  aldehyde,  is 
treated  with  a  10  per  cent  solution  of  the  barium  salt, 
the  resulting  insoluble  compound  is  separated  and  steam 
distilled,  so  regenerating  the  aldelyde.  The  method 
has  been  applied  to  benzaldehyde,  its  homologues 
and  derivatives,  cinnamaldehyde,  citral,  citronellal, 
and  salicylaldehyde.  The  barium  salts  of  the  follow- 
ing- acids  have  been  employed:  naphthionic,  sulphan- 
ilic,  ;;z-aminobenzoic,  2-hydroxy-^-naphthylamine-3- 
carboxylic,  and  ^-naphthylamine-5-sulphonic. 

(9)  OTHER  DERIVATIVES  OF  ALDEHYDES  AND 
KETONES. 

All  primary  acid  hydrazides  yield  readily  crystal- 
line compounds  with  aldehydes  and  ketones.  Nitro- 
sobenzhydrazide  is  especially  well  adapted  for  the 
separation  of  small  quantities  of  carbonyl  compounds, 
from  large  bulks  of  solvent,  in  cases  where  phenylhydra- 
zine  gives  slimy  precipitates.  It  is  also  useful  for  work 
with  the  sugars.* 

MonopyrocatecJwlcarbonic  hydrazide . 

HO.C6H4.O.CO.NH.NH2 

quickly  condenses  with  aldehydes  but  not  with  ketones ; 
the  resulting  compounds  crystallize  easily,  are  soluble 
in  alkalis,  and  are  reprecipitated  by  acids.3 

1  Journ.  Chem.  Soc.  82  (1902),  i.  376.      German  Patent,  124,  229. 

2  T.  Curtius,  J.  pr.  50  [2]  (1894),  283;  B.  28  (1895),  523- 

3  A.  Einhorn,  Ann.  300  (1898),  136. 


94  RADICLES   IN   CARBON    COMPOUNDS. 

HYDRAZIDE  DERIVATIVES    OF  KETONES,   vide  p.    165. 

A  description  of  OTHER  DERIVATIVES  OF  ALDEHYDES 
AND  KETONES  is  given  on  p.  166. 

DETERMINATION  OF  CARBONYL  DERIVATIVES  BY  HY- 
DROLYSIS, vide  p.  167. 

DETERMINATION  OF  METHYLENE  >CH2.1 

A  quantity  of  substance  sufficient  to  yield  0.20-0.25 
gram  phloroglucide  is  heated  during  2  hours  at  7O°-8o° 
with  water  (5  cc),  hydrochloric  acid  sp.  gr.  1.19 
(15  cc),  and  slight  excess  of  pure  phloroglucinol  in 
aqueous  solution  (15  cc).  The  precipitate  is  collected 
on  a  Gooch  porcelain  filter,  and  the  filtrate  again 
heated  with  more  concentrated  acid ;  if  a  further  pre- 
cipitate forms  another  experiment  must  be  made  using 
water  (5  cc),  concentrated  sulphuric  acid  (10  or  20  cc), 
and  phloroglucinol  solution  (10  cc).  After  filtration, 
the  phloroglucide  C_H6O3  is  dried  at  95°-98°  during  4 
hours,  and  weighed,  with  due  precautions  against  the 
absorption  of  moisture.  One  part  of  formaldehyde  and 
I  part  of  methylene  =4.6  and  9.857  parts  of  phlo- 
roglucide respectively.  The  method  is  sufficiently  ac- 
curate to  distinguish  easily  the  presence  of  I,  2,  or  3 
CH2  groups  in  the  molecule;  it  has  been  chiefly  tested 
with  formaldehyde  and  its  condensation  derivatives 
with  sugars,  but  appears  to  be  generally  applicable. 

DETERMINATION  OF  THE  PROPENYL  AND  ALLYL  GROUPS 
AND  OF  ETHYLENE  IN  AMINES,  vide  pp.  167,  1 68. 

1  G.  H.  A.  Clowes,  B.  32  (1899),    2842. 


CHAPTER  IV. 

i  i 

DETERMINATION  OF  THE  AMINO  NH2 ;  NITRILE,  CN ; 
AMIDE  CO.NH2 ;  IMINO  NH;  METHYL  IMINO  N'.CH3  ; 
AND  ETHYL  IMINO  N.C2H5  GROUPS. 

DETERMINATION    OF    THE    AMINO    GROUP 

(NH2). 

Different  methods  are  employed  for  the  determina- 
tion of  the  amino  group  according-  to  whether  the  com- 
pound is  an  aromatic  or  aliphatic  amine. 

(A)  Determination  of  Aliphatic  Amino  Groups. 

These  are  determined: 

(1)  By  means  of  nitrous  acid. 

(2)  By  analysis  of  the  salts  and  double  salts. 

(3)  By  acylation. 

(4)  Titration  vuith  cznanthaldehyde. 

(i)  Nitrous  Acid  Method. — Alphatic  amines  react 
with  nitrous  acid  in  accordance  with  the  equation 

RNH2  +  HNO2-^ROH  +  N2  +  H2O. 

The  first  method  suggested  for  the  determination  of  the 
nitrogen  consisted  in  liberating  it  in  an  atmosphere  of 
nitric  oxide,  which  was  then  absorbed  by  means  of  fer- 

95 


96  RADICLES    IN   CARBON    COMPOUNDS. 

rous  sulphate  solution.1  The  following  process  is  much 
more  convenient.  The  substance,  dissolved  in  just 
sufficient  dilute  sulphuric  acid  to  give  a  neutral  solu- 
tion, is  placed  in  a  flask  provided  with  a  trebly  bored 
stopper.  If  possible  a  distillation  bulb  should  be  em- 
ployed having  a  capillary  tube  fused  to  it.  A  dropping 
funnel  is  fitted  to  the  stopper  of  the  flask,  the  leg  being 
drawn  out,  bent  upwards,  and  passed  below  the  surface 
of  the  liquid  ;  it  is  filled  with  distilled  water  at  the  com- 
mencement of  the  experiment.  The  third  tube  of  the 
flask,  or  the  side  tube  of  the  distillation  bulb,  is  fitted 
by  means  of  an  air-tight  stopper  almost  to  the  bottom 
of  a  second  distillation  bulb.  This  has  its  side  tube 
suitably  bent,  and  connected  with  a  Leibig's  potash 
bulb  filled  with  potassium  permanganate  solution  (3 
per  cent), containing  sodium  hydroxide  (about  I  gram). 
The  gas  delivery-tube  is  attached  to  the  potash  bulb, 
and  dips  below  the  mouth  of  the  measuring  vessel, 
which  is  half  filled  with  mercury  and  half  with  potas- 
sium hydroxide  (sp.  gr.  =  1.4).  The  air  is  displaced 
from  the  apparatus  by  a  slow  current  of  carbonic 
anhydride,  which  may  be  obtained  pure  and  free  from 
air  by  dropping  dilute  sulphuric  acid  (50  per  cent,  sp, 
gr.  =  1.4)  into  a  concentrated  solution  of  potassium 
carbonate  (sp.  gr.  =  1.45-1. 5). 3  When  the  air  is 
expelled,  the  measuring  tube  is  placed  in  position,  and 
a  slight  excess  of  potassium  nitrite  solution  added  by 
means  of  the  dropping-funnel,  The  reaction  is  com- 


1  R.    Sachsse  and   W.  Kormann,  Landwirthsch.    Vers.-Stationen,  27, 
321.     Z.  anal.  Ch.  14,  380. 

2  Fr.  Blau,  M.  13,  280 . 


DETERMINATION    OF    THE   AMINO   GROUP,  ETC.      97 

pleted  by  heating  on  the  water-bath  and  the  addition 
of  a  little  dilute  sulphuric  acid. 

(2)  Analysis  of  Salts  and  Double  Salts. — The  prepa- 
ration of  most  of  these  is    too  well  known  to  require 
comment.     Of    the     simple    salts    the    hydrochlorides 
sometimes  can  only  be  induced  to  crystallize  in  a  state 
of  purity  by  the  action  of  anhydrous  hydrogen  chloride 
on  a  solution  of  the    base   in  ether,  free  from   alcohol 
and  moisture.      The  cJir  ornate  and  pier  ate,1  especially 
the  latter,    usually  crystallize   readily.      The  mcrcuri- 
cJiloride,  RHgCl3,  has   occasionally  been  of  service  in 
cases  where  the  chloraurate  or  chloroplatinate  are  oily 
or  unstable  (cf.  p.   105). 

(3)  Acylation. — This    is    described    in    connection 
with  the  aromatic  amines,  p.   106. 

(4)  Titration  with  cenantJialdeliyde.      The  base  (2-4 
grams)   is  dissolved  in  benzene  (2—3  vols.),  a  few  pea- 
sized  fragments  of  fused  calcium  chloride  added,    and 
the  aldehyde  pure,  or  in  benzene  solution,  gradually 
run  in  from  a  burette.      The  operation  is  completed  so 
soon  as  further  addition  of  the  aldehyde  fails  to  produce 
a  turbidity.      1 39  grams  aldehyde  =  2  grams  hydrogen 
in  the  amine.2    Vide  also  p.  169. 

(B)  Determination  of  Aromatic  Amino  Groups. 

The  following  methods  are  employed  for  the  deter- 
mination of  primary  aromatic  amines : 

(1)  Titration  of  the  salts. 

(2)  Preparation  of  diazo  derivatives. 

(a)  By  conversion  into  an  azo  dye. 

1  Delepine,  Bull.  15,  53.  2  H.  Schiff,  Ann.  159  (1871),  158. 


98  RADICLES    IN    CARBON    COMPOUNDS. 

(£)  Indirect  method. 

(c)  Azoimide  method. 

(d)  By  means  of  the  Sandmeyer-Gattermann  re- 

action. 

(3)  Analysis  of  salts  and  double  salts. 

(4)  Acylation. 

(5)  Alkylation. 

(l)    TITRATION    OF    THE    SALTS.1 

(I)  Salts  of  aromatic  amines,  in  aqueous  or  alcoholic 
solution,   give    an  acid    reaction  with    rosolic  acid    or 
phenolphthalein.      The  salt,  preferably  the  hydrochlo- 
ride  or  sulphate,  is  dissolved  in  water  or  dilute  alcohol, 
phenolphthalein  added,  and  the  titration  carried  out  in 
the  ordinary  manner  with  potassium  hydroxide. 

(II)  Many  free  bases  may  be  directly   titrated   with 
hydrochloric  acid,   methyl   orange   being   used   as   an 
indicator. 

(III)  A  large  number  of  alkaloids  may  be  determined2 
by  dissolving  about  0.2  gram  in   a  known  volume  of 
N/2O  hydrochloric  acid  (30  cc), adding,  in  excess,  neu- 
tral iodopotassium  iodide  solution  (Wagner's  reagent), 
containing  iodine  (10  grams),  and  potassium  iodide  (15" 
grams)  in  I    liter.      The  mixture  is  vigorously  shaken 
until  no  further  precipitate  is   formed   and  the  super- 
natant liquid  is  dark  red  and  perfectly  clear;  it  is  then 
diluted  to  100  cc.      After  filtering,  50  cc  are  decolorised 
by  means  of  a  few  drops  of  sodium  thiosulphate  solution 
(10  per  cent),  and  titrated  with  N /2O  potassium  hydrox- 
ide, in  presence  of  phenolphthalein.     Should  the  alkaloid 

1  Menschutkin,  B.  16,  316. 

8  H.  M.  Gordin,  Ibid.  32  (1899),  2871. 


DETERMINATION    OF   THE   AMINO   GROUP,  ETC.      99 

yield  a  less  soluble  compound  with  potassium  mercuric 
iodide  (Mayer's  reagent)  than  with  Wagner's  reagent, 
the  former  is  substituted  for  the  latter.  '  The  N/2O  acid 
is  best  standardized  in  the  above  manner  by  means  of 
some  pure  alkaloid  such  as  morphine.  The  following 
factors  may  be  of  service:  I  cc  acid  will  be  equivalent 
to  0.0184  gram  hydrastine,  0.0160  gram  strychnine, 
0.0102  gram  caffeine  (cryst.),  0.0139  gram  atropine, 
and' 0.0146  gram  cocaine,  if  it  is  found,  by  experiment, 
that  i  cc  acid  =  0.0137  gram  morphine  (anhydrous). 
In  the  titration  of  caffeine  50  instead  of  30  cc  acid 
should  be  employed.  Berberine  and  colchicine  can 
not  be  determined  by  this  method. 

(2)    PREPARATION    OF   DIAZO    DERIVATIVES. 

(a)  Conversion  of  tJie  Base  into  an  Azo  Dye.1 
The  base,  for  example  aniline  (0.7-0.8  gram),  is 
dissolved  in  hydrochloric  adduce),  and  diluted  with 
water  and  ice  to  100  cc.  A  titrated  solution  of 
"R-salt,"  sodium  2:3:6  naphtholdisulphonate,  is  pre- 
pared, of  such  strength  that  a  liter  is  equivalent  to 
about  10  grams  of  naphthol.  The  solution  of  the 
hydrochloride  is  cooled  to  O°,  sodium  nitrite  added  in 
quantity  equivalent  to  the  aniline  or  other  base  present, 
and  the  mixture  gradually  poured  into  a  measured 
quantity  of  the  sulphonate  solution,  which  has  been 
treated  with  sodium  carbonate  in  excess.  The  dye  pro- 
duced is  precipitated  by  means  of  sodium  chloride,  fil- 
tered, and  the  nitrate  tested  with  benzenediazonium  chlo- 
ride solution,  and  with  R-salt  to  determine  whether  the 

1  Reverdin  and  De  la  Harpe,  Ch.  Ztg.  13,  I.  387,  407;  B.  22,  1004. 


100  RADICLES    IN   CARBON    COMPOUNDS. 

latter  or  the  base  is  in  excess.  By  repeating  the  ex- 
periment it  is  possible  to  find  the  volume  of  R-salt  solu- 
tion necessary  to  combine  with  the  diazo-derivative  of 
the  base  originally  taken. 

The  following  method  has  been  applied  to  aniline, 
ortho-  and  paratoluidine,  metaxylidine,  and  sulphanilic 
acid.1  A  known  quantity  of  the  base  is  diazotized  and 
made  up  to  a  certain  volume ;  it  is  then  immediately 
added  from  a  burette  to  a  solution  of  "  Schafer's  salt," 
sodium  2 : 6-naphthol  sulphonate,  of  known  strength, 
which  has  been  mixed  with  sodium  chloride  and  a  few 
drops  of  ammonium  hydroxide,  the  addition  being  con 
tinued  so  long  as  a  precipitate  forms.  The  end  point 
is  determined  by  bringing  a  drop  of  the  clear  superna- 
tant liquor  into  contact  with  a  drop  of  the  diazo-solution 
on  filter  paper.  The  progress  of  the  reaction  can  be 
followed  by  the  intensity  of  the  red  color  produced  at 
the  point  of  contact  of  the  two  liquids  on  the  paper. 
Towards  the  end  of  the  operation  the  color  is  only 
visible  in  the  middle  of  the  moist  circle.  In  the  case 
of  a  readily  soluble  dye,  such  as  that  given  by  sulpha- 
nilic acid,  the  paper  must  be  covered  with  a  thin  crust 
of  sodium  chloride  and  the  test  portions  allowed  to  fall 
on  to  it;  more  sodium  chloride  must  also  be  added  to 
the  naphtholsulphonate  solution. 

The  method  can  be  applied2  as  a  colourimetric  one  to 
the  determination  of  very  small  quantities  of  methylic 
anthranilate  in  ethereal  oils,  or,  where  larger  quantities 
of  this  compound  are  being  dealt  with,  an  alkaline 
solution  of  /?-naphthol  may  be  substituted  for  the  disul- 

1  R.  Hirsch,  B.  24,  324.  2  E.  Erdmann,  Ibid.  35  (1902),  24. 


DETERMINATION    OF    THE    AMINO   GROUP,  ETC.    IOI 

phonate.  The  resulting  dye  is  insoluble  in  water. 
The  end  point  is  determined  as  in  the  case  of  the 
'  *  R-salt. ' '  The  method  is  stated  1  not  to  be  quantita- 
tive when  the  ester  is  mixed  with  large  quantities  of 
terpenes,  but  it  sharply  distinguishes  between  methylic 
anthranilate  and  methylic  methylanthranilate.  When 
these  occur  together  a  combination  of  the  two  methods 
is  advantageous,  one-half  the  precipitate  (see  below) 
being  diazotised,  and  the  other  titrated  and  hydrolysed. 
The  difference  between  the  results  gives  the  amount  of 
methylic  methylanthranilate  present.  Where  the 
latter  is  absent  the  determination  may  be  made  more 
simply  by  dissolving  the  oil2  in  dry  ether  (2-3  parts), 
cooling  to  o°  or  lower,  and  gradually  adding  a  well- 
cooled  mixture  Oi"  concentrated  sulphuric  acid  and  ether 
(1:5  vols.).  The  resulting  precipitate  is  collected 
on  a  filter,  washed  well  with  dry  ether,  dissolved  in 
water,  and  titrated  with  N/2  potassium  hydroxide  and 
phenolphthalem.  After  the  titration,  excess  of  the 
potash  is  added,  the  liquid  heated  for  half  an  hour  on  the 
water-bath,  and  the  product  titrated  with  N/2  sulphuric 
acid.  The  percentage  of  ester  (^')  in  the  oil  is  calcu- 
lated by  the  formula  x  =  100 — • where  a 

=  cc  potash  required  for  the  hydrolysis,  and  s  the 
weight  of  substance  taken.  The  first  titration  serves 
as  a  check.  Vide  also  p.  172. 

(b)  Indirect  Method. 

This  is  extensively  employed  for  technical  purposes, 
and  consists  of  an  inversion  of  a  method  for  the  deter- 

1  G.  Hesse  and  O.  Zeitschel,  B.  35  (1902),  2355. 
*  Ibid.  34  (1901),  2966. 


102  RADICLES    IN    CARBON    COMPOUNDS. 

mination  of  nitrous  acid.1  The  base  is  treated  with 
three  times  its  weight  of  hydrochloric  acid,  and  the 
mixture  dissolved  in  so  much  water  that  the  solution 
contains  o.oi  to  o.  I  gram  equivalent  of  the  base.  The 
solution  is  maintained  at  o°  by  means  of  ice,  and 
titrated  with  sodium  nitrite  solution,  potassium  iodo- 
starch  paper  being  used  as  indicator;  the  operation  is 
ended  when  a  drop  of  the  mixed  liquids  gives  a  blue 
coloration  with  the  paper.  The  nitrite  solution  should 
be  about  N/io.  It  is  prepared2  by  dissolving  the 
nitrite  in  300  parts  of  cold  water,  and  its  titre  is  ob- 
tained by  adding  N/io  potassium  permanganate  solu- 
tion until  a  distinct  permanent  red  coloration  is 
obtained;  two  or  three  drops  of  dilute  sulphuric  acid 
are  now  added,  then,  immediately,  excess  of  the  per- 
manganate, the  liquid  is  made  strongly  acid  with  sul- 
phuric acid,  heated  to  boiling,  and  the  excess  of 
permanganate  determined  by  means  of  N/io  oxalic 
acid  solution. 

(c)  Azoimide  Method* 

This  is  specially  applicable  to  compounds  containing 
amino  groups  linked  to  different  nuclei.  The  azoimides 
are  prepared  by  the  action  of  ammonia  on  the  diazoper- 
bromides4  and,  on  account  of  the  large  content  of  nitro- 
gen in  the  former,  their  analysis  is  peculiarly  well 
adapted  for  the  determination  of  the  number  of  diazo- 

1  A.  G.  Green  and  S.  Rideal,  Ch.  N.  49,  173. 

2  L.    P    Kinnicutt  and  J.   U.   Nef,  Am.   Chem.  Journ.  5,  388.     Fre- 
senius'  Zschr.  25,  223. 

3  Meldola  and  Hawkins,  Ch.  N.  66,  33. 

4  Griess,  Ann.  137,  65. 


DETERMINATION    OF    THE    AMINO   GROUP,  ETC.    103 

tisable  groups  in  the  molecule.  Details  of  the  method 
of  preparing  azomides  have  been  given  by  various 
chemists.1 

(d )  Sandmeyer 2-  Gattermann '  s 3  Reaction . 

The  determination  of  the  amino  group  is  often  con- 
veniently accomplished  by  converting  it  into  the  diazo- 
derivative  and  replacing  the  nitrogen  by  chlorine ;  as 
a  rule  the  diazo-compound  is  not  isolated.  The  fol- 
lowing example4  will  serve  to  illustrate  the  method: 
Metanitraniline  (4  grams)  and  concentrated  hydro- 
chloric acid,  sp.  gr.  =  1.17  (7  grams),  are  dissolved 
in  water  (100  grams),  and  10  per  cent  cuprous  chloride 
solution  (20  grams)  added ; '  the  mixture  is  heated 
almost  to  boiling  in  a  reflux  apparatus,  and  sodium 
nitrite  (2.5  grams),  dissolved  in  water  (20  grams),  is 
gradually  run  in  by  means  of  a  dropping  funnel,  the 
mixture  being  well  shaken  during  the  addition.  Nitro- 
gen is  evolved,  and  a  heavy  brown  oil  collects  which 
solidifies  when  cooled  with  ice,  and  is  purified  by  dis- 
tillation. As  a  rule  these  chloro-derivatives  are  vola- 
tile with  steam ;  if  not  they  are  purified  by  means  of 
ether  or  benzene. 

The  above  method  is  the  one  originally  proposed  by 
Sandmeyer;  by  means  of  it  chloro-compounds  may 
be  readily  obtained  from  diamines  which  cannot  be 
diazotised  in  the  ordinary  manner.  The  cuprous  chlo- 
ride employed  is  prepared  by  boiling  crystallized  cop- 
per sulphate  (25  parts)  and  anhydrous  sodium  chloride 

1  Nolting,   Grandmougin,    and  O.  Michel,   B.  25,  3328.     Curtius  and 
Dedichen,  J.  pr.  [2].  50,  250. 

2  B.  17,  1633.  3  Ibid.  23,  1218.  *  Ibid.  17,  2650. 


IO4  RADICLES    IN    CARBON    COMPOUNDS. 

(12  parts)  with  water  (50  parts);  some  sodium  sulphate 
crystallizes  out,  and  when  the  reaction  is  completed 
the  product  is  mixed  with  concentrated  hydrochloric 
acid  (100  parts),  and  copper  turnings  (13  parts),  the 
mouth  of  the  flask  is  loosely  closed,  and  the  mixture 
boiled  until  the  liquid  becomes  colorless.  Sufficient 
concentrated  hydrochloric  acid  is  now  added  to  bring 
the  weight  of  the  mixture  to  203.6  parts,  since  only 
6.4  parts  of  the  copper  actually  dissolve,  197  parts  of 
solution  are  obtained  which  contains  0.2  gram  mole- 
cules of  CuCl.  The  filtered  solution  may  be  retained 
a  considerable  time  in  a  well-closed  bottle  containing 
carbonic  anhydride.1 

Cupric  chloride  is  reduced  to  cuprous  chloride  by 
hypophosphorus  acid,2  hence,  in  place  of  the  cuprous 
chloride  solution  prepared  according  to  the  foregoing 
method,  a  mixture  of  hydrochloric  acid,  copper  sul- 
phate solution,  and  sodium  hypophosphite  may  be 
employed.3 

The  use  of  finely  divided  copper  instead  of  cuprous 
chloride  has  been  suggested  ;4  amongst  other  advantages 
the  reaction  proceeds  at  the  ordinary  temperature,  and 
the  yield  is  frequently  improved.  The  copper  is  pre- 
pared by  adding  zinc-dust,  through  a  fine  sieve,  to  a 
cold  saturated  solution  of  copper  sulphate  until  only  a 
faint  blue  color  remains,  the  product  is  well  washed  by 
decantation  with  large  quantities  of  water,  the  remain- 
ing zinc  removed  by  digestion  with  highly  dilute  hydro- 
chloric acid,  and  the  copper  filtered  and  washed  with 
water  until  neutral ;  it  is  preserved  in  the  form  of  a  paste 

1  Feitler,  J.  pr.  4,  68.  2  A.  Cavazzi,  Gazz.  16,  167. 

3  A.  Angeli,  Ibid.  21,  2,  258.         *  Gattermann,  B.  23,  1218. 


DETERMINATION   OF   THE    AMINO   GROUP,  ETC.    10$ 

in  well-closed  bottles.  The  following  example  will 
illustrate  the  method  of  working:  Aniline  (3.1  grams) 
is  mixed  with  40  per  cent  hydrochloric  acid  (30 
grams),  and  water  (15  cc),  the  liquid  is  cooled  to  O° 
and  a  saturated  aqueous  solution  of  sodium  nitrite  (2.3 
grams)  quickly  added,  the  liquid  being  vigorously 
stirred,  preferably  by  means  of  a  turbine;  the  reaction 
is  completed  in  one  minute.  Finely  divided  copper  (4 
grams)  is  now  gradually  added  to  the  diazo  solution, 
which  is  well  stirred;  the  reaction  requires  15-30  min- 
utes for  completion,  this  is  signalized  by  the  particles 
of  copper  ceasing  to  be  carried  to  the  surface  of  the 
liquid  by  the  escaping  bubbles  of  nitrogen.  The  chlo- 
robenzene  is  removed  by  steam  distillation. 

(3)    ANALYSIS    OF    SALTS    AND    DOUBLE    SALTS. 

The  remarks  on  the  salts  of  aliphatic  amines  (p.  97) 
apply  generally  to  those  of  the  aromatic  series;  the 
accumulation  of  negative  groups  in  their  molecules  often 
completely  prevents  the  formation  of  salts.  As  a  rule 
the  chloraurate  contains  one  atom  of  gold  for  each 
amino  group,  and  the  chloroplatinate  one  atom  of  plati- 
num to  two  amino  groups,  but  aminopyridine  platino- 
chloride  has  the  formula  (C6H6N2)2.HaPtCl6.1  Sometimes 
the  alky  I  haloid  salts  are  of  service,  but  many  primary 
bases  do  not  form  them.'2  In  presence  of  secondary  or 
tertiary  amino  groups  the  method  yields  fallacious  re- 
sults. The  production  of  salts  is  not  confined  to  nitro- 
gen derivatives,  many  oxygen  compounds  (oxonium 
bases)  yield  them,  dim  ethyl  pyrone  gives,  amongst 


1  M.  15,   176.  2  Hofmann,  Jahresbericht  (1863),  p.  421. 


106  RADICLES    IN   CARBON    COMPOUNDS. 

others,  a  chloroplatinate  (C7H8O.2)2IlftC\6l  and  certain 
phenol  derivatives  yield  hydrochlorides  and  picrates.2 
"  Sulphonium  "  3  and  "  carbonium  "  4  bases  have  also 
been  described. 

Abnormal  chloraurates  of  isopropylamine,  piperi- 
dine,  i-methylpiperidine,  2-5-dimethylpyrrolidine  and 
quinoline  have  also  been  described,5  they  have  the 
formula  (NR4)2AuCl5,  and  are  readily  resolved  into  the 
normal  derivatives  NR4AuCl4  +  NR4Cl.  Cf.  p.  173. 

(4)    ACYLATION. 

The  methods  of  acylation  described  for  the  deter- 
mination of  hydroxyl  are  also  applicable  to  the  ammo 
group  (cf.  pp.  6,  97,  112). 

A  number  of  amines,  notably  «-naphthylamine,  may 
be  acetylated  in  aqueous  solution.6  The  following 
method  gives  excellent  results  with  aniline;  some  modi- 
fications would  probably  have  to  be  introduced  for  other 
compounds.  The  amine  solution,  freed  from  tin,  is 
highly  concentrated,  neutralized  with  soda,  and  satu- 
rated sodium  acetate  solution  added  in  quantity  equiva- 
lent to  85  per  cent  erf  the  hydrochloride  present;  10 
cc  of  this  solution  are  titrated  with  N/io  potassium 
hydroxide,  with  litmus  as  indicator.  To  the  remainder 
of  the  solution  a  sealed  bulb  containing  a  weighed  quan- 

1  Collie  and  Tickle,  Journ.  Chem.  Soc.  75,  712. 

2  C.  Bulow  &  H.  Grotowsky,  B.  35  (1902),  1800.     Cf.  A.  Baeyer  & 
V.  Villiger,  Ibid.  34  (1901),  2679  et  seq. 

3  F.  Kehrmann,  Ibid.  32  (1899),  2602. 

4  P.  Walden.  Ibid.  35  (1902),  2018. 

5  G.  Fenner  and  J.  Tafel,  Ibid.  32  (1899),  3220. 

6  J.  Pinnow,  Ibid.  33  (1900),  418. 


DETERMINATION   OF    THE    AMINO   GROUP,  ETC.    TO? 

tity  of  acetic  anhydride  is  added,  the  bulb  broken,  and 
the  contents  rapidly  mixed.  A  second  titration  of  10 
cc  of  this  liquid  is  then  made,  any  solid  *  acetyl  deriva- 
tive being  removed  by  means  of  a  dry  filter. 

Thiacctic  acid  readily  yields  acetyl  derivatives  with 
aromatic  amines  on  simple  mixing.1  Benzylidenaniline 
yields  an  unstable  additive  product,  and  trichlorethy- 
lidinediphenamine  has  one  C6H5NH  group  acetylated, 
and  the  other  replaced  by  SH  on  treatment  with 
thiacetic  acid.'2 

The  action  of  benzenesul phonic  chloride,  p- toluene- 
sulphonic  chloride,  p-bromobenzenesulphonic  chloride,  or 
m-nitrobenzenesulphonic  chloride  often  affords  a  means 
of  separating  primary,  secondary,  and  tertiary  amines, 
as  the  first  two  interact,  and  the  third  does  not.  The 
reaction  is  carried  out  as  in  the  case  of  hydroxyl  deriv- 
atives (cf.  p.  6).  The  products  of  primary  and  secon- 
dary amines  frequently  differ  considerably  in  solubility.3 

Amino  acids  such  as  alanine,  leucine,  and  tyrosine 
readily  yield  benzoyl  derivatives  by  treatment  with  ben- 
zoyl  chloride  and  sodium  bicarbonate.4 

The  separation  of  such  compounds  is  often  more 
readily  accomplished  by  use  of  benzenesulphonic  chlo- 
ride (1.5  mol.),  and  potassium  hydroxide  solution  (22 
per  cent).5  A  better  reagent  for  hydroxyamino  acids 
and  complicated  derivatives  of  the  glycylglycine  series 
is  fi-naphthalenesulphonic  chloride',  it  is  readily  pre- 

1  B.  Pawlewski,  B.  31  (1898),  661.     Ibid.  35  (1902),  no. 

2  A.  Eibner,  Ibid.  34  (1901),  657. 

3  W.  Solonina,  J.  Russ,  Chem.  Soc.  31  (1899),  640.  Journ.  Chem.  Soc. 
78(1900),  i.  147.     W.  Marckwald,  B.  32  (1899),  3512. 

4  E.  Fischer,  Ibid.  32,  2454. 

5  E.  Fischer,  Ibid.  33  (1900)1  238°  I  34  (i9OI)>  448- 


108  RADICLES    IN   CARBON   COMPOUNDS. 

pared  l,  and  most  conveniently  purified  by  distillation 
under  a  pressure  of  0.3  mm  and  subsequent  crystalliza- 
tion from  benzene.  The  ammo  acid  is  dissolved  in  N 
sodium  hydroxide  solution  (i  mol.)  and  mixed  with  the 
chloride  (2  mol.)  in  ethereal  solution;  the  mixture  is 
shaken  by  a  machine  at  the  ordinary  temperature,  and 
at  intervals  of  I  — 1.5  hours  three  times  the  above  quan- 
tity of  N  alkali  is  added.  At  the  conclusion  of  the 
experiment  the  aqueous  liquid  is  separated,  filtered, 
treated,  if  needful,  with  animal  charcoal,  and  the  naph- 
thalenesulphonic  derivative  precipitated  by  hydrochloric 
acid  in  excess.2  Vide  also  pp.  174,  177. 

(5)    ALKYLATION.       (Cf.  pp.    149,   178.) 

Amino  groups  in  certain  leuco-bases  and  coloring 
matters  are  easily  methylated  3  by  heating  a  solution  of 
the  substance  with  zinc-dust,  hydrochloric  acid,  and 
formaldehyde  at  75°— 80°;  the  decolorised  liquid  is  sub- 
sequently oxidised,  either  by  exposure  to  air,  or  by  lead 
peroxide  and  acetic  acid. 

The  remarks  on  dimethylsulphate  (p.  32)  apply  also 
to  the  alkylation  of  amino-  or  imino-compounds.  It  is 
usually  employed  in  ethereal  solution  without  alkali.4 

DETERMINATION  OF  THE  NITRILE    GROUP 

(C:N.) 

The  nitrile  radicle  is  determined  by  hydrolysis,  the 
resulting  ammonia  or  acid  being  collected. 

(a)  Prolonged  boiling  with  hydrochloric  acid  is 
usually  sufficient  to  cause  hydrolysis;  the  product  is 

1  J.  pr.  47  [2],  94.  2  E.  Fischer,  B.  35  (1902),  3779. 

3  M.  Prud'homme,  Bull.  23  (1900),  iii.  69. 

*  F.  Ullmann  and  P.  Wenner,  B.  33  (1900),  2476. 


DETERMINATION    OF    THE    AMINO    GROUP,  ETC.    1 09 

then  treated  with  alkali  in  excess,  and  the  ammonia 
distilled  off  and  determined  in  the  ordinary  manner. 

(b)  a-Hydroxycyancamphor     is     unstable     towards 
alkalis,  and    resists    hot    hydrochloric    acid,   and    sul- 
phuric acid   (60  per  cent),   but  is    readily  hydrolysed 
by  solution   in  fuming  sulphuric   acid  at  the  ordinary 
temperature,  and   subsequent  dilution.      The  resulting 
mixture  of  amides  was  converted  into   acids  by  pro- 
longed heating   with  fuming  hydrobromic  acid.1 

(c)  Should  the  hydrolysis  only  take  place  in  the  pres- 
ence of  aqueous  or  alcoholic  alkali  an  apparatus  similar 
to  that  employed  in  Zeisel's  method  for  the  determina- 
tion of  methoxyl  is  used  (Figs.  2,  3,  5,  pp.  39,  40,  42). 
A  current    of   air,   freed    from  carbonic  anhydride,   is 
passed  through  the  apparatus,  and  the  bulbs  are  filled 
with  concentrated  alkali  solution ;  the  ammonia  is  most 
readily  determined    as  the    chloroplatinate.       At    the 
conclusion   of  the  experiment  the  flask  A  will  contain 
the  alkali  salt  of  the  acid  produced,  and  may  be  treated 
by  one  of  the  methods  described  for  the  determination 
of  carboxyl  (Chapter  II). 

(d)  The  hydrolysis  of  nitriles  2  may  be  hindered  by 
stereo-chemical  influences,    especially  in    the    case   of 
diortho-substituted  compounds,3  just  as  the  correspond- 
ing acids  esterify   with  difficulty,  or  not  at  all,  under 
the   influence   of   hydrogen   chloride.      The   nitriles  in 
question,  although  they  resist  prolonged  heating  at  a 

1  A.  Lapworth  and  E.  M.  Chapman,  Journ.  Chem.  Soc.  79  (1901),  378. 

'  M.  and  J.  II,  p.  545. 

3  A.  W.  v.  Hofmann,  B.  17,  1914  ;  18,  1825  ;  Stallburg,  Ann.  278, 
209.  Cain,  B.  28,  969.  V.  Meyer  and  Erb,  Ibid.  29,  834,  foot-note. 
Sudborough,  Journ.  Chem.  Soc.  67,  60 1. 


IIO  RADICLES    IN    CARBON    COMPOUNDS. 

high  temperature  in  a  sealed  tube  with  hydrochloric 
acid,  are  all  converted  into  amides  by  continued  boil- 
ing with  alcoholic  potassium  hydroxide.1  The  amide 
is  hydrolysed  to  the  acid  in  the  manner  described  in 
the  following  section.  Cyanmesitylene  a  requires  boiling 
during  seventy-two  hours  with  alcoholic  potassium  hy- 
droxide, and  triphenylacetonitrile 3  needs  fifty  hours 
boiling  with  the  same  reagent  to  produce  the  amide. 
Some  nitriles  that  are  otherwise  resistant  may  be  hy- 
drolysed by  heating  at  I2O°-I3O°  during  an  hour  with 
90  per  cent  sulphuric  acid  (20—30  parts).  The  resulting 
amide  is  converted  into  the  acid  by  means  of  nitrous 
acid4  (cf.  following  section),  Unhydrolysable  nitriles 
have  also  been  described.5 

(e)  Certain  amides  may  be  obtained  by  the  action  of 
alkaline  hydrogen  peroxide  at  4O°6  on  the  nitriles;  the 
resulting  compounds  are  then  treated  in  the  manner 
described  on  p.  1 1 1. 

(/")  Some  nitriles  may  be  reduced  to  the  correspond- 
ing amine  by  means  of  zinc  and  hydrochloric  acid7  or 
sodium  and  alcohol.8 

DETERMINATION  OF  THE  AMIDO  GROUP 
(CO.NH2). 

The  amido  group  is  determined  by  hydrolysis,  in  a 
similar  manner  to  the  nitrile  group  (preceding  section). 

1  Bouveault,  S.  p.  80.      Hantzsch  and  Lucas,  B.  28,  748. 

2  V.  Meyer  and  Erb,  Ibid.  29,  834.          A  V.  Meyer,  Ibid.  28.  2782. 
*  Sudborough,  Jour.  Chem.  Soc    67,   60 1.     Munch.   B.  29,  64. 

6  J.  Deinert,  J.  pr.  52,  [2]  (1895),  431.      Ra<lzi<zewsky,  B-  7,  18,  355. 
J.  K.  Auwers  and  A.  J.  Walker,  Ibid.  31  (1899),  3044. 
6  Claus  and  Wallhaum,  J.  pr.  56,  52. 
1  Mendius,  Ann.  121  (1862),  129.     &  Ladenburg,  B.  18  (1885),  2956- 


DETERMINATION    OF    THE    AMINO    GROUP,  ETC.    I  1 1 

The  method  employed  for  the  hydrolysis  of  very  stable 
amides  !  is  best  illustrated  by  its  application  to  the  prep- 
aration of  triphenylacetic  acid.2  The  finely  divided 
amide  (0.2  gram)  is  gently  warmed  with  concentrated 
sulphuric  acid  (i  gram)  and  the  clear  solution  cooled  in 
ice,  sodium  nitrite  (0.2  gram),  dissolved  in  water  (i 
gram),  cooled  to  o°,  is  added  very  slowly  by  means  of  a 
capillary  tube ;  when  the  addition  is  complete  the  test- 
tube  containing  the  mixture  is  placed  in  a  beaker  of 
water  and  gradually  heated.  The  evolution  of  nitro- 
gen commences  at  6o°-7O°,  and  is  completed  at 
8o°-9O° ;  finally  the  tube  is  heated  in  boiling  water  for 
3-4  minutes,  but  not  longer.  When  cool,  ice  is  added 
to  the  liquid,  the  precipitated  solid  collected,  and  puri- 
fied by  solution  in  dilute  sodium  hydroxide  and  precipi- 
tation with  sulphuric  acid.  It  is  highly  desirable  to 
use  the  exact  theoretical  quantity  of  sodium  nitrite  dis- 
solved in  the  smallest  possible  volume  of  water.3  The 
amide  may  also  be  dissolved  in  sulphuric  acid  (20-30 
per  cent),  and  to  the  boiling  liquid  sodium  nitrite  solu- 
tion (5—10  per  cent)  added;  (1.5—2  mol.  for  each 
CO.NH2  group).  The  boiling  is  continued  until  gas 
evolution  ceases.4 

/-Hydroxyvaleric  amide  is  completely  hydrolysed 
only  if  it  is  boiled  down  to  dryness  with  dilute  hydro- 
chloric acid,  or  heated  in  a  reflux  apparatus  for  f  hour  in  a 
current  of  air. 5  Stereo-chemical  influences  are  effective  in 

1  Bouveault,  Bull.  [3],  g,  370.     2  G.  Heyl  and  V.  Meyer,  B.  28,  2783. 

3  Sudborough,  Jour.  Chem.  Soc.  67,  604. 

4  L.  Gattermann,  B.  32  (1899),  1118. 

6  E.  L.  Neugebauer,  Ann.  227  (1885),  105. 


112  RADICLES    IN    CARBON   COMPOUNDS. 

hindering  the  hydrolysis  of  amides,  as  they  are  in  that 
of  the  nitriles.1    Vide  also  p.   179. 

DETERMINATION    OF     THE     IMINE    GROUP 

(NH). 

The  following  methods  are  employed  for  the  deter- 
mination of  the  imine  group: 

(1)  Acetylation. 

(2)  Alkylation. 

(3)  Analysis  of  salts. 

(4)  Elimination  of  the  imidogen  as  ammonia. 

(l)  ACETYLATION  OF  IMINES  (SECONDARY  AMINES). 

Imines  may  be  acetylated  by  any  of  the  methods 
employed  for  the  determination  of  hydroxyl  which  are 
described  in  Chapter  I.  The  reaction  usually  takes 
place  without  difficulty,  and  therefore  an  indirect 
method2  may  be  utilized.  A  weighed  quantity  of  the 
compound  (about  I  gram)  is  placed  in  a  flask,  fitted  to  a 
reflux  apparatus,  and  acetic  anhydride  (about  2  grams) 
quickly  added.  The  anhydride  should  be  added  from 
a  suitably  stoppered  vessel,  which  is  weighed  before 
and  after  the  addition.  The  mixture  is  allowed  to  re- 
main at  the  ordinary  temperature  during  about  thirty 
minutes,  water  (50  cc)  is  then  added,  and  the  liquid 
heated  on  the  water-bath  during  forty-five  minutes;  the 
solution  is  now  cooled,  diluted  to  a  definite  volume, 
and  titrated  with  sodium  hydroxide  of  known  strength, 
phenolphthalem  being  used  as  indicator. 

1  A  bibliography  of  the  subject  is  given  in  M.  and  J.  II,  p.  545. 

2  Reverdin  and  De  la  Harpe.  B.  22,  1005. 


DETERMINATION   OF   THE    AMINO   GROUP,  ETC.    113 

The  process  was  specially  worked  out  for  methylani- 
line,  hence,  for  other  imines,  the  duration  of  the  heat- 
ing and  the  temperature  require  modification  according 
to  the  readiness  with  which  they  react.  It  may  be 
desirable  to  heat  in  a  sealed  tube,  or  in  a  dry  closed 
flask,  the  mixture  being  constantly  shaken,  and  the 
anhydride  diluted  with  ten  volumes  of  dimethylaniline.1 


(2)    ALKYLATION    OF  IMINES. 

Some  inline  groups  may  be  methylated  by  dissolving 
the  compound  in  alkali  and  gradually  adding  methylic 
iodide;  the  mixture  is  constantly  shaken  and  main- 
tained at  the  ordinary  temperature.  The  method  has 
been  extensively  employed  in  the  investigation  of  purin 
and  uric  acid  derivatives2  (cf.  p.  108). 

(3)    ANALYSIS    OF   SALTS. 

The  remarks  on  the  analysis  of  salts  of  primary 
amines  (pp.  97,  105)  apply  equally  to  those  of  secon- 
dary ones. 

(4)    ELIMINATION   OF   IMIDOGEN   AS    AMMONIA. 

The  hydrolysis  of  the  acid  imides  is  usually  carried  out 
by  prolonged  boiling  with  hydrochloric  acid  either  in  an 
open  vessel  or  under  pressure  in  a  sealed  tube.  The 
liquid  is  then  made  alkaline,  the  ammonia  or  amine 
volatilized  into  hydrochloric  acid,  and  the  excess  of 

1  H.  Giraud,  Bull.  (3),  II.  142. 

2  E.  Fischer,  B.  28,  2479 ;  30,  569,  3094  ;  32,  453.  C.  (1897),  II,  157. 


RADICLES  IN  CARBO 


X  CO 


MPOUNDS. 


the  latter  determined  by  titration  or,  in  some  cases,  by 
means  of  the  chloroplatinate.    Vide  also  p.  180. 

DETERMINATION  OF  METHYL  IMINE 

(NCH.).' 

The  hydriodides  of  methylated  bases  eliminate 
methyl  iodide  at  2OO°-3OO°  in  accordance  with  the 
equation  R2NCH3.HI->R2NH  +  CH3I ;  the  iodide  may 
be  determined  by  Zeisel's  method  (cf.  p.  38  et  seq.). 
The  apparatus  employed  is  iden- 
tical with  that  of  Zeisel  except 
the  vessel  in  which  the  sub- 
stance is  heated.  This  is  shown 
in  Fig.  13,  and  consists  of  a 
double  flask  a  b  connected  by 
means  of  a  cork  with  the  vessel  c. 
The  method  is  modified  accord- 
ing to  whether  one  or  more  alkyl 
groups  are  linked  to  nitrogen, 
and,  in  the  latter  case,  whether 
these  are  to  be  determined  suc- 
cessively; finally  the  presence  of  alkyloxy  groups,  in 
addition  to  methyl  imine,  demands  special  manipulation. 


(/)   Determination  with  only  one  A  Iky  I  linked  to 


Nitrogen. 


The     compound     (0.15-0.3     gram)    as    free    base, 
nitrate,    or  haloid   salt    is    placed    in   the   flask  a  with 


379- 


Herzig   and   II.    Meyer,    B.    27,319.     M.  15,613;   16,599;   18, 


DETERMINATION    OF    THE    AMINO   GROUP,  ETC.    115 

sufficient  hydriodic  acid  (sp.  gr.  =  1.68  —  1.72)  to 
fill  the  vessel  c  to  the  mark  de\  the  object  of  this  is  to 
retain  any  volatile  basic  compounds  which  might  be 
carried  over  by  the  carbonic  anhydride.  In  addition 
to  the  acid,  the  flask  a  also  contains  ammonium  iodide 
in  quantity  equal  to  5-6  times  that  of  the  substance  em- 
ployed. The  vessel  C  is  connected  directly  with  the 
condenser  (Figs.  2,  3,  5,  pp.  39,  40,  42);  it  should  con- 
tain a  little  red  phosphorus,  if  much  iodine  is  liberated 
in  a,  as  is  usually  the  case  when  nitrates  are  employed. 
The  flask  b  is  filled  with  asbestos,  a  little  of  which  is 
also  placed  in  a  to  facilitate  the  boiling.  A  more  rapid 
current  of  carbonic  anhydride  is  used  than  in  the  de- 
termination of  methoxyl,  so  as  to  remove  the  methyl 
iodide  as  quickly  as  possible  and  prevent  its  entering 
into  combination  with  the  other  compounds  produced, 
consequently  two  absorption  flasks  with  silver  nitrate 
must  always  be  employed.  The  heating  is  done  by 
means  of  a  sand-bath  of  copper  with  a  sheet-iron  bot- 
tom; it  is  divided  into  two  equal  portions  by  a  par- 
tition, and  is  of  such  a  shape  as  to  permit  the  flasks 
being  immersed  in  the  sand  up  to  the  \vs\tfg.  The 
flask  a  is  first  heated,  carbonic  anhydride  being  passed 
through  the  apparatus;  a  portion  of  the  acid  distils  into 
b  and  some  into  c.  Gradually  the  second  chamber  of 
the  bath  is  filled  with  sand,  and  b  then  directly  heated. 
All  the  acid  soon  accumulates  in  c,  the  carbonic 
anhydride  bubbling  through  it  whilst  the  flask  a  con- 
tains only  the  hydriodide  of  the  base.  The  commence- 
ment of  the  decomposition  is  indicated  by  a  turbidity 
in  the  silver  nitrate  solution,  and  it  occurs  soon  after 
the  acid  has  been  expelled  from  the  flask  b.  The  rq- 


Il6  RADICLES   IN   CARBON   COMPOUNDS. 

mainder  of  the  experiment  is  carried  out  exactly  as  in 
the  methoxyl  determination. 


(2)  Determination  with  two  or  more  A  Iky  I  Groups 
linked  to  Nitrogen. 

This  is  carried  out  in  the  manner  described  on 
p.  1 14.  When  the  operation  is  completed  the  appa- 
ratus is  allowed  to  cool  in  a  current  of  carbonic 
anhydride,  c  is  detached  from  the  condenser,  and  by 
cautious  tilting  the  acid  poured  from  it  back  to  b, 
whence  it  will  pass  spontaneously  to  a.  A  fresh  quan- 
tity of  silver  nitrate  is  placed  in  the  absorption  flasks, 
and  the  apparatus  is  ready  to  heat  again.  The  opera- 
tion is  repeated  until  the  quantity  of  silver  iodide  ob- 
tained is  equivalent  to  an  amount  of  alkyl  weighing 
less  than  0.5  per  cent  of  the  substance  employed.  It 
is  important  to  conduct  the  determinations  at  the  low- 
est possible  temperature,  and  therefore  a  thermometer 
is  placed  in  the  sand-bath  which  is  never  allowed  to 
exceed,  by  more  than  40°,  the  temperature  (2OO°-25OC) 
at  which  the  silver  nitrate  solution  first  becomes  turbid. 
When  several  alkyl  groups  are  present,  it  is  advisable 
to  use  more  ammonium  iodide  than  otherwise,  about  5 
grams  in  a,  and  2-3  grams  in  b.  Each  decomposition 
requires  some  two  hours  for  completion,  and  three 
treatments  are  amply  sufficient  even  though  the  com- 
pound contains  three  or  four  alkyls. 


DETERMINATION    OF   THE   AMINO   GROUP,  ETC.    1 1/ 


(3)  Successive  Determination  of  the  Alkyl  Groups. 

The   alkyl   groups   may  be   successively   eliminated 
from  feebly  basic  compounds  such  as       u  A 

caffeine  or  theobromine.  In  place  of 
the  vessel  previously  employed  (Fig. 
13),  the  substance  is  heated  in  one 
of  the  shape  shown  in  Fig.  14.  It  is 
immersed  in  a  sand-bath  to  the  mark 
ab ;  after  heating,  the  acid  is  allowed 
to  flow  back  to  the  flask,  a  little  am- 
monium iodide  is  added,  and  the 
heating  repeated, — the  operation  be- 
ing performed  a  third  time,  with  the 
addition  of  more  ammonium  iodide, 
if  three  alkyl  groups  are  present. 


FIG.  14. 


(4)  Determination    of   Methyl    I  mine    in    Presence   of 
Methoxyl. 

The  methyl  imine  may  be  determined  in  presence  of 
me-thoxyl  by  heating  the  hydriodide  alone  in  the  flask 
a  (Fig.  13);  it  is,  however,  preferable  to  add  to  it  hy- 
driodic  acid  (10  cc),  and  heat  the  flask  in  an  oil-  or 
glycerol-bath  so  that  scarcely  any  distils  over  into  b. 
When  the  operation  is  ended,  which  is  indicated  by  the 
silver  nitrate  solution  becoming  clear,  the  temperature 
is  raised,  and  the  acid  distilled  off  until  only  so  much 
remains  in  a  as  is  usually  employed  for  the  methyl 
imine  determination  (p.  114).  During  the  distillation 
the  silver  nitrate  solution  remains  quite  clear,  and 
the  methoxyl  determination  is  completed.  A  fresh 
portion  of  silver  nitrate  is  taken,  the  excess  of  acid  re- 


Il8  RADICLES   IN    CARBON   COMPOUNDS. 

moved  from  b  and  c,  ammonium  iodide  added,  and  the 
methyl  imine  determination  commenced  in  the  manner 
described  on  p.  1 14. 

(5)   General  Remarks  on  the  Method.1 

The  purity  of  the  hydriodic  acid  and  ammonium 
iodide  must  be  ascertained  by  means  of  a  blank  ex- 
periment (cf.  p.  41). 

The  method  is  applicable  to  all  compounds  which 
can  form  a  hydriodide,  even  though  this  may  not  be 
capable  of  isolation,  and  accurate  results  are  obtained 
by  the  use  of  any  salt  or  double  salt  which  is  not  ex- 
plosive and  does  not  contain  sulphur.  Quantitative 
results  are  also  obtained  in  the  case  of  many  com- 
pounds, such  as  /j-ethylpyrroline,  methylcarbazole,  and 
dimethylparabanic  acid,  which  do  not  form  salts.  Cer- 
tain substances  containing  the  group  CO.N.NCH3  elimi- 
nate the  CH3  almost  as  readily  as  methoxyl  derivatives,2 
this  is  especially  the  case  with  i-phenyl-4-methylani- 
linourazole.  In  such  circumstances  therefore  failure  of 
a  compound  to  react  with  hydriodic  acid  at  the  lower 
temperature  indicates  the  absence  of  methoxyl,  but 
the  converse  does  not  apply  without  further  investi- 
gation. The  limits  of  error  lie  between  -f-  3  and  —  I  5 
per  cent  of  the  total  alkyl,  consequently  the  presence 
or  absence  of  one  such  group  can  only  be  determined 
with  certainty  when  the  theoretical  difference  in  com- 
position for  one  alkyl  exceeds  2  per  cent,  or,  in  other 

1  J.  Herzig  and  H.  Meyer,  M.  18  (1897),  379.     Journ.  Chem.  Soc,  74, 
(1898),  i.  53- 

2  M.  Busch,  B.  35  (1902),  1565. 


DETERMINATION    OF    THE    AMINO   GROUP,  ETC.    IIQ 

words,    when    the    molecular    weight    of  the   original 
methylated  compound  is  less  than  650. 

In  considering  the  results  obtained  it- is  necessary  to 
observe  the  colour  of  the  silver  iodide;  should  this  be 
dark  or  gray  instead  of  yellow,  the  error  is  almost 
always  positive.  100  parts  Agl  =  6.38  parts  of  CH3. 
Vide  also  p.  180. 

DETERMINATION  OF  ETHYL  IMINE  (NC2H5). 

The  method1,  of  determination  is  exactly  the  same  as 
that  described  for  methyl  imine  (p.  114  et  seq.).  100 
parts  Agl  =  12.34  parts  of  C2H5. 

DIFFERENTIATION  OF  THE  METHYL  IMINE 
AND  ETHYL  IMINE  GROUPS. 

The  method  of  determination  by  means  of  the  alkyl 
iodides  does  not,  as  a  rule,  distinguish  between  ethyl 
imine  and  methyl  imine;  in  doubtful  cases  it  is  neces- 
sary to  distil  a  considerable  quantity  of  the  hydriodide 
of  the  base,  and  purify  and  identify  the  alkyl  iodide 
which  is  evolved.  A  second  method  consists  in  distil- 
ling the  base  with  potassium  hydroxide,  evaporating 
the  distillate  to  dryness  with  hydrochloric  acid,  separat- 
ing the  organic  hydrochlorides  from  ammonium  chlo- 
ride by  means  of  absolute  alcohol  and  chloroform,  and 
converting  the  Dormer  into  picrates,  chloroplatinates, 
etc.,  which  may  then  be  identified;  the  method  must, 
however,  be  used  with  caution,  as  it  may  lead  to  errone- 
ous results. 

1  J.  Herzig  and  H.  Meyer,  B.  27,  319.     M.  15,  613;  16,  599. 

2  Ciamician  and  Boeris,  B.  29,  2474. 


CHAPTER  V. 

DETERMINATION  OF  THE  DIAZO  GROUP  (R.N:N);  OF 
THE  HYDRAZIDE  RADICLE  (NH.NH2);  OF  THE  NITRO- 
GROUP  (N02);  OF  THE  IODOSO-GROUP  (10);  OF  THE 
IODOXY-GROUP  (I02);  OF  THE  PEROXIDE  GROUP 
J  IODINE  NUMBER. 


DETERMINATION    OF    THE    DIAZO    GROUP 
(R.NrN.R). 

The  aliphatic  and  aromatic  diazo-compounds  (diazo- 
nium  derivatives)  are  differently  constituted,  hence  the 
methods  adapted  for  their  determination  are  not 
identical. 

(A)  Aliphatic  Diazo-compounds   /C—  CH< 

The  following  methods  are  employed:1 

(1)  Tit  rat  ion  witJi  iodine. 

(2)  Analysis  of  tlie  iodo-derivatives. 

(3)  Determination  of  tJie  nitrogen  in  the  wet  way. 

* 
(l)    DETERMINATION     OF    THE     NITROGEN    BY   TITRA- 

TION    WITH     IODINE. 

This  reaction  takes  place  in  accordance  with  the 
equation  CHN2.COOR  +  I2-*CHI2,COOR  +  N2. 

1  Curtius,  J.  pr.  146,  422. 

120 


DETERMINATION   OF   THE   DIAZO   GROUP,  ETC.   121 

Rather  more  than  the  theoretical  quantity  of  iodine 
is  accurately  weighed,  dissolved  in  absolute  ether,  and 
added,  by  means  of  a  burette,  to  a  known  quantity  of 
the  diazo-compound  also  in  ethereal  solution;  the  end 
of  the  reaction  is  indicated  by  a  sharp  change  in  the 
colour  of  the  diazo-compound  from  lemon  yellow  to 
red ;  towards  the  conclusion  of  the  titration  the  reac- 
tion is  facilitated  by  warming  the  liquid  on  the  water- 
bath.  The  excess  of  iodine  solution  is  run  into  a 
tared  flask,  the  ether  cautiously  removed,  and  the 
residue  weighed.  Unless  the  compound  employed  is 
in  a  high  state  of  purity,  the  change  of  colour  in  the 
liquid  takes  place  long  before  all  the  nitrogen  has 
been  expelled. 

(2)  ANALYSIS  OF  THE  IODINE  DERIVATIVE. 
The  iodine  in  the  iodo-compound  may  be  deter- 
mined in  the  ordinary  manner,  or  the  following  simpler 
method,  first  used  in  the  investigation  of  diazoaceta- 
mide,1  may  be  employed.  A  weighed  quantity  of 
the  substance  is  placed  in  a  tared  beaker,  dissolved  in 
a  little  absolute  alcohol,  and  iodine  added  until  a  per- 
manent red  coloration  is  obtained.  The  alcohol  is 
volatilized  on  the  water-bath,  the  excess  of  iodine 
removed  by  cautious  heating,  and  the  crystalline  resi- 
due weighed.  In  this  case,  also,  the  compound  em- 
ployed must  be  pure. 

(3)    DETERMINATION    OF   THE    NITROGEN    IN   THE 

WET    WAV. 

On  account  of  the  great  volatility  of  the  aliphatic 
ethereal  diazocarboxylates  the  method  of  nitrogen 

1  Curtius,  J.  pr.  146,  423. 


122 


RADICLES    IN    CARBON   COMPOUNDS. 


FIG.  15. 


determination  described  on  p.  95  cannot  be  employed. 
This  difficulty  is  overcome  l  by  the  use  of  the  apparatus 

shown  in  Fig.  15.  A  is  a. 
large  gas  cylinder  contain- 
ing water,  r  a  capillary  tube, 
the  upper  open  end  of 
which  rises  a  little  above 
the  level  of  the  water  in 
A.  E  is  a  gas-measuring 
tube,  B  a  small  condenser 
fitted  to  the  little  flask  C 
by  means  of  a  rubber  stop- 
per ;  through  this  a  platinum  wire  also  passes.  It  is  bent 
in  the  manner  shown  and  carries  a  glass-stoppered  vessel 
such  as  is  employed  in  vapor  density  determinations. 
The  flask  C  is  partially  filled  with  well  boiled,  highly 
dilute  sulphuric  acid,  the  compound  (about  0.2  gram) 
weighed  into  the  small  vessel  s,  and  the  apparatus 
fitted  together  air-tight.  When  the  air  in  the  appa- 
ratus is  in  equilibrium  with  the  atmosphere,  which  can 
readily  be  observed  if  a  drop  of  water  is  placed  in  r, 
the  volume  of  air  in  the  eudiometer  tube  is  read  off, 
and  the  temperature  noted.  The  vessel  s  is  now 
dropped  into  the  acid,  which  is  gradually  heated  to 
boiling ;  the  decomposition  is  completed  in  a  few  min- 
utes. The  apparatus  is  allowed  to  cool  completely, 
the  level  of  water  in  and  outside  the  tube  E  adjusted, 
and  the  volume,  temperature,  and  pressure  noted;  the 
difference  in  volume  from  the  previous  reading  gives 
the  quantity  of  nitrogen  evolved.  As  a  rule  the 


1  Curtius,  J    pr.  146,  417. 


DETERMINATION   OF   THE   DIAZO   GROUP,  ETC.   12$ 

atmospheric  pressure   does  not  materially  change  dur- 
ing the. experiment. 

Compounds  containing  an  amino  as  \vell  as  a  diazo- 
group,  such  as  diazoacetamide,  may  be  decomposed 
by  means  of  dilute  hydrochloric  acid;  after  the  evolu- 
tion of  nitrogen  is  completed  the  ammonium  chloride 
in  the  flask  c  may  be  precipitated  with  hydrochloro- 
platinic  acid  and  the  amino  and  diazo  nitrogen  thus 
separately  determined  in  one  operation. 

(B)  Aromatic    Diazo    Compounds.     (Diazonium  Deriva- 
tives C.N.OH.) 

I 

The  diazo  group  in  aromatic  compounds  is  usually 
determined  by  the  preceding  method1  (3),  p.  121,  but 
it  is  preferable  to  employ  a  Lunge's  nitrometer  and 
40  per  cent  sulphuric  acid.2  Sulphuric  acid,  sp.  gr.  = 
1.306,  has  a  vapor  tension  of  9.4  mm  at  I5°.3 

A  modification  consists  in  dissolving  the  diazonium 
salt  in  ice-water,  adding  hydrochloric  acid,  and  dis- 
placing the  air  by  means  of  carbonic  anhydride  while 
the  solution  is  in  a  freezing-mixture.  Cuprous  chlo- 
ride is  then  added,  and  the  liquid  gradually  heated 
to  boiling.  The  necessary  correction  for  dissolved 
air  is  ascertained  by  a  blank  experiment.4  On 
account  of  the  action  of  acids  in  producing  intra.- 

1  Knoevenagel,  B.   23,  2997.     v.  Pechmann  and  Frobenius,  Ibid.  27, 
706. 

2  Bamberger.  Ibid.  27,  2598. 

3  Regnault. 

4  H.  Goldschmidt  and  A.  Merz,  Ibid.  29, 1369  ;  30,  671;  A.  Hautzsch, 
Ibid.  33  (1900),  2159. 


124 


RADICLES    IN    CARBON    COMPOUNDS. 


molecular  rearrangement  of  diazonium  derivatives,  it  is 
desirable  to  reduce  the  time  required  to  expel  the  air 
from  the  apparatus  and  to  avoid  the  necessity  for  work- 
ing at  o°.  The  apparatus  shown  in  Fig.  16  is  de- 


FIG.  16. 

signed  to  accomplish  this.  It  has  been  used  with  great 
success  for  the  determination  of  diazo  nitrogen  in 
diazoamino  derivatives.1  It  consists  of  a  thin-walled 
test  tube  10—12x31  cm.  The  tubes  are  inserted  flush 
with  the  rubber  stopper.  The  substance  is  placed  in 
the  tube,  the  leg  of  the  funnel,  which  is  drawn  to  a 
fine  point,  is  filled  with  recently  boiled  water.  The 
tube  d  is  connected  with  an  air-pump,  c  with  a  car- 
bonic anhydride  apparatus,  and  a  with  a  eudiometer;  b  is 
a  three-way  cock ;  a  is  closed,  the  apparatus  exhausted, 
carbonic  anhydride  introduced,  and  the  exhaustion 
and  introduction  of  carbonic  anhydride  repeated  twice 
more.  The  air  in  a  is  then  expelled  by  a  very  rapid 

1  H.  Mehner,  J.  pr.  63  [2]  (1901),  304. 


DETERMINATION   OF   THE   DIAZO    GROUP,  ETC.  125 

current  of  carbonic  anhydride,  b  closed,  the  funnel 
filled  with  cone,  hydrochloric  acid,  and  enough 
introduced  into  the  test-tube  to  fill  it  one  fifth.  The 
liquid  is  now  rapidly  heated  to  boiling  and  the  evolu- 
tion of  nitrogen  takes  place  speedily.  When  the  ex- 
periment is  completed,  the  greater  part  of  the  gas  in 
the  apparatus  is  expelled  by  means  of  boiled  water, 
the  remainder  by  carbonic  anhydride.  No  aminoazo 
derivatives  are  produced,  the  method  is  very  rapid,  and 
at  least  as  accurate  as  that  of  Dumas. 

DETERMINATION  OF  THE    HYDRAZIDE 
GROUP  (NH.NH2). 

Either  the  oxidation  or  iodometric  method  may  be 
employed. 

(l)    OXIDATION    OF    HYDRAZIDES.1 

Boiling  Fehling's  solution  hydrolyses  acid  phenyl- 
hydrazides,  and  oxidizes  the  resulting  phenylhydrazine, 
the  nitrogen  of  which  is  evolved  quantitatively  and  deter- 
mined by  the  method  described  en  p.  74.  The  com- 
pound is  dissolved,  if  possible,  in  water  or  alcohol ; 
hydrazides  which  do  not  dissolve  are  weighed  into  a 
small  stoppered  vessel  which  is  fixed  mouth  downwards 
in  the  hole  of  the  stopper  otherwise  occupied  by  the 
funnel  A,  Fig.  1 1,  p.  75,  and  is  dropped  into  the  boiling 
solution  by  means  of  a  glass  rod  of  the  same  volume. 
Insoluble  compounds  may  also  be  treated  according  to 

1  H.  Strache  and  S.  Iriizer,  M.  14,  37.  Holleman  and  de  Vries, 
Rec.  10,  229.  De  Vries,  B.  27,  1521;  28,  2611.  Petersen,  Z.  An. 


126  RADICLES   IN    CARBON    COMPOUNDS. 

the  following  method:1  100  cc  Fehling's  solution, 
and  150  cc  alcohol,  with  a  few  fragments  of  porce- 
lain, are  placed  in  a  500  cc  flask  fitted  with  a  doubly 
bored  rubber  stopper.  In  the  one  hole  the  tube  con- 
taining the  weighed  substance  is  placed,  through  the 
other  the  end  of  an.  inclined  condenser  passes.  The 
contents  of  the  flask  are  boiled,  and  the  open  end  of  the 
condenser  connected  with  a  bent  tube  terminating  in 
a  short  leg  which  dips  below  water.  When  no  more 
air  is  expelled,  a  measuring  vessel  full  of  water  is  placed 
over  the  end  of  the  tube,  and  the  vessel  with  the  sub- 
stance pressed  into  the  flask  by  means  of  a  rod.  Con- 
tinued boiling  for  a  short  time  suffices  to  liberate  all 
the  nitrogen. 

In  some  cases  it  is  desirable  to  recover  the  acid  on 
account  of  its  rarity,  or  to  remove  it  in  order  to  facili- 
tate the  determination,  as  in  the  case  of  stearic  acid, 
the  potassium  salt  of  which  causes  the  liquid  to  froth 
over.  This  can  be  accomplished,  if  the  acid  is  spar- 
ingly soluble  in  water  or  dilute  hydrochloric  acid,  by 
boiling  the  hydrazide  with  concentrated  hydrochloric 
acid,  during  several  hours ;  the  solution  is  made  up  to 
100  cc,  the  organic  acid  removed  by  means  of  a  dry 
filter,  the  first  few  drops  of  the  filtrate  rejected,  and  50 
cc  of  the  remainder  taken  for  the  determination.  This 
method  of  hydrolysis  does  not  distinguish  between 
hydrazides  and  hydrazones,  as  the  latter  are  also  acted 
upon  by  hydrochloric  acid.  Ortho-  and  paratolyl- 
hydrazides  are  oxidized  in  the  same  manner  as  phenyl- 
hydrazides,  so  that  the  method  is  also  applicable  to 
them.* 

1  H.  Meyer,  M.  18,  404.  *  M.  14,  38. 


DETERMINATION    OF    THE    DIAZO    GROUP,  ETC. 

Hydrochloroplatinic  acid  oxidizes  hydrazine  hydro- 
chloride  in  accordance  with  the  equation 


N2H4.2HC1  +  2H2PtCl6-^N2  +  ioHQ  +  2PtCl2; 

the  evolved    nitrogen  is    determined    by    the    method 
described  on  p.   12  I.1 

Hydrazine  salts  may  be  titrated  by  potassium  per- 
manganate in  presence  of  sulphuric  acid,  provided  the 
concentration  of  the  latter  is  6-12  per  cent.2  The  re- 
action is  represented  by  the  equation 

ioN. 


(2)    IODOMETRIC    METHOD.3 

Phenylhydrazine  and  iodine  react  in  accordance  with 
the  following  equation  : 

.  C.H.NH.NH,  +  2l,-»3HI  +  N2  +  C.H.I. 

The  interaction  is  quantitative,  in  highly  dilute  solu- 
tion, with  iodine  present  in  excess.  The  determination 
is  made  by  adding  to  a  known  volume  of  N/io  iodine 
solution,  the  highly  dilute  solution  of  the  base  or  its 
hydrochloride,  obtained  by  hydrolysis,  p.  109;  the 
excess  of  iodine  is  then  titrated  in  the  ordinary 
manner. 

In  presence  of  dilute  sulphuric  acid,  iodic  acid  oxi- 
dizes phenylhydrazine,  and  this  reaction  may  also  be 
employed  for  the  determination.  The  strength  of  the 
iodic  acid  solution  is  ascertained  by  means  of  sulphurous 
acid  of  known  titre;  it  is  then  added,  in  excess,  to  the 

1  Curtius,  J.  pr.  147,  37.  2  Petersen,  Z.  An.  5,  3. 

3  E.  v.  Meyer,  J.  pr.  149,  115. 


128  RADICLES    IN   CARBON   COMPOUNDS. 

highly  dilute  solution  of  phenylhydrazine  and  sulphuric 
acid,  and  the  mixture  again  titrated. 

Arsenic  anhydride  and  phenylhydrazine  react  in  ac- 
cordance with  the  equation 


Two  methods  of  analysis  have  been  worked  out  based 
on  this  reaction,  (i)  Phenylhydrazine  hydrochloride 
is  agitated  with  arsenic  acid  solution  in  excess,  and  the 
liquid  titrated  with  a  uranium  salt,  which  i.  also  em- 
ployed to  determine  the  content  of  arsenic  acid  in  the 
original  solution.  (2)  After  treatment  with  arsenic 
acid  as  before,  the  arsenious  acid  produced  is  deter- 
mined by  means  of  iodine.  The  following  solutions 
are  required  : 

Iodine  (N/io); 

Sodium  hydroxide  (200  grams  in  I  liter)  ; 

Sodium  hydrogen  carbonate  (cold  saturated  solution)  ; 

Starch  solution  (freshly  prepared)  ; 

Arsenic  acid  solution  (125  grams  arsenic  anhydride 
dissolved  in  hot  water  (450  cc)  and  cone,  hydro- 
chloric acid  (150  cc),  cooled,  filtered,  and  made  up  to 
I  liter  with  glacial  acetic  acid). 

The  phenylhydrazine  hydrochloride,  or  free  base, 
(0.2  gram)  is  mixed  with  the  arsenic  acid  solution  (60 
cc),  and  the  liquid  boiled  steadily  by  the  help  of  a 
small  platinum  spiral  in  a  reflux  apparatus  for  40  min- 
utes. Water  (200  cc)  is  added,  and  the  liquid  neu- 
tralized with  sodium  hydroxide,  phenolphthalein  being 
used  as  indicator.  It  is  now  made  just  acid  with 
hydrochloric  acid,  mixed  with  sodium  hydrogen  car- 


DETERMINATION    OF   THE    DIAZO    GROUP,  ETC.     1  29 

bonate  solution  (60  cc),  and  titrated  with  iodine  in  the 
usual  manner.  I  part  As2O3  =  0.5454  parts  CgHgN^1 
To  the  above  methods  may  be  added  tjie  titration 
of  phenylhydrazine  with  hydrochloric  acid;  rosolic  acid 
or  methyl-orange  is  used  as  indicator,  and  tolerably 
accurate  results  are  obtained.2 

DETERMINATION     OF     THE     NITRO-GROUP 

(N02). 

(A)  Titration  Method.3 

Organic  nitro-compounds  are  reduced  to  amino- 
derivatives  by  the  action  of  stannous  chloride,  in 
presence  of  hydrochloric  acid,  in  accordance  with  the 
equation 


R.NO2  +  3SnCl2  +  6HC1-»R.NH2  +  sSnCl,  +  2H2O  ; 

the  unchanged  stannous  chloride  is  determined  by 
titration,  and,  from  the  quantity  which  has  reacted, 
the  number  of  nitro-groups  in  the  original  compound 
may  be  ascertained.  Solution  of  iodine,  or  of  potas- 
sium permanganate,  is  employed  for  the  titration  —  the 
latter  when  much  colour  is  developed.  The  method  is 
inapplicable  to  trinitrophenol  or  nitronaphthalene.4 

1  H.  Causse,  Bull.    19  [3],  (1898),  147. 

2  Strache  and  Iritzer. 

3  H.  Limpricht,  B.  n,  35;  Spindler,  Ann.  224,  288. 

4  Jenssen,  J    pr.   78,   193.     S.   W.  Young  and  R.   E.   Swain,  J.  Am. 
(1897),    19,  812-814.     Journ.   Chem.   Soc.  (1898),  74,1!,  186.     P.  Alt- 
mann,  J.  pr.  (1901)  63  [2],  370. 


130  RADICLES    IN    CARBON   COMPOUNDS. 

Reagents  Required. 

(1)  Stannoiis  Chloride  Solution .      Tin  (150  grams)  is 
dissolved  in   concentrated  hydrochloric   acid,  the  clear 
liquid  decanted,  mixed  with  concentrated  hydrochloric 
acid  (50  cc),  and  diluted  to  I  liter. 

(2)  Sodium   Carbonate  Solution.    Anhydrous  sodium 
carbonate    (90   grams)   and   sodium   potassium  tartrate 
(i  20  grams)  are  dissolved  in  water  and  diluted  to  I  liter. 

(3)  Iodine   Solution.      Iodine    (12.54  grams)  is  dis- 
solved in  potassium  iodide  solution, and  the  liquid  made 
up  to    i    liter,   it  will  then    be  approximately  N/io;  if 
exactly  so  i  cc  =  0.0059  gram  Sn  =  0.0007655  gram 
N02. 

(4)  Starch  Solution.      This  must  be  dilute,  recently 
prepared,  and  filtered. 

Potassium  Permanganate  Solution.  It  should  be 
N/io,  and  may  be  used  instead  of  the  iodine,  its 
strength  being  determined  by  means  of  iron. 

(I)  MctJiod  of  Determination  for  Non-volatile 
Compounds. 

After  the  titre  of  the  stannous  chloride  has  been 
ascertained,  the  nitro-compound  (about  0.2  gram)  is 
placed  in  a  100  cc  glass-stoppered  flask,  stannous 
chloride  solution  (ro  cc)  added,  and  the  liquid  warmed 
during  thirty  minutes.  When  cool,  the  mixture  is  di- 
luted to  the  mark,  and.  after  shaking,  10  cc  transferred 
to  a  beaker  by  means  of  a  pipette;  a  little  water  is 
added,  then  the  sodium  carbonate  solution,  until  the 
precipitate  which  first  forms  is  wholly  dissolved ;  after 
the  addition  of  a  little  starch, the  iodine  solution  is  run 
in  until  a  permanent  blue  colouration  is  produced. 


DETERMINATION    OF   THE    DIAZO   GROUP,  ETC.   13! 

The  results  of  the  analysis  are  calculated  according 
to  the  formula  NO2  —  (a  —  b).  0.000765  5  gram,  where 
tf—  the  number  of  cc  of  iodine  solution  equivalent  to  I 
cc  of  the  stannous  chloride  solution,  and  £  =  the  number 
of  cc  of  iodine  solution  required  in  the  determination. 

If  it  is  desired  to  use  the  potassium  permanganate, 
10  cc  of  the  acid  liquid,  withdrawn  as  described  above, 
is  boiled  with  ferric  chloride,  and  the  ferrous  chloride 
produced  is  determined  in  the  ordinary  manner. 

(II)  Modified  Method  for  Volatile  Compounds. 

Volatile  nitro-compounds  are  weighed  in  a  test-tube 
about  30  cm  by  8  mm,  closed  with  a  cork;  the  cork 
is  removed,  and  the  tube,  together  with  the  stannous 
chloride,,  placed  in  a  second  larger  one,  20  cm  by 
13-15  mm,  which  is  then  sealed.  The  larger  tube 
may  be  of  thin-walled,  readily  fusible  glass,  as  it  will 
only  be  subjected  to  a  very  slight  pressure.  The  tube 
is  heated  in  the  water-bath  during  1-2  hours,  and  well 
shaken  occasionally;  it  is  then  cooled,  the  contents 
completely  washed  into  a  roo-cc  graduated  flask,  and 
treated  in  the  manner  described  in  the  preceding  sec- 
tion. The  use  of  a  sealed  tube  is  sometimes  advisable 
in  the  case  of  non-  volatile  compounds  with  which  low 
results  may  be  obtained  by  heating  in  the  stoppered 
bottle. 

Many  aromatic  nitro-compounds  evolve  nitrogen 
quantitatively  when  treated  with  phenylhydrazine  at  or 
a  little  above  100°.  (Cf.  p.  132.  )1 

R.N02  +  3C6H,NH.NH2 


R.  Walter,  J.  pr.  53  [2],  (1896),  437. 


132  RADICLES   IN    CARBON   COMPOUNDS. 

(B)  Diazo  Method.1 

Should  the  preceding  method  fail  to  give  decisive 
results  the  nitro-compound  must  be  reduced  to  the 
amino-derivative  and  this  treated  in  the  manner  de- 
scribed on  pp.  95,  103.  As  an  example,  metanitro- 
benzaldehyde  may  be  converted  into  metachloro- 
benzaldehyde  by  one  operation.2  It  is  dissolved  in 
concentrated  hydrochloric  acid  (6  parts),  stannous 
chloride  (4.5  parts)  added,  and  after  the  reduction, 
without  precipitating  the  tin,  it  is  mixed  with  the  cal- 
culated quantity  of  sodium  nitrite  and  an  equal  weight 
of  finely  divided  copper.  Vide  also  p.  181. 

DETERMINATION    OF    THE    NITROSO    (NO) 
GROUP.3 

The  method  depends  on  the  fact  that,  under  suit- 
able conditions,  simple  nitroso-compounds  react  with 
phenylhydrazine  in  accordance  with  the  equation : 

R.NO  +  CGH.NH.NH2->RN  +  H2O  +  C6H6  +  N2. 

The  apparatus  employed  is  shown  in  Fig.  17,  p.  133. 
The  substance  (0.1-0.2  gram)  is  weighed  into  the  300 
cc  flask  R,  and  dissolved  in  glacial  acetic  acid  (20-30 
cc).  The  apparatus  is  then  fitted  together,  and  the  air 
displaced  by  a  slow  stream  of  carbonic  anhydride.  This 
may  require  several  hours.  When  most  of  the  air  has 
been  removed  from  the  flask  and  condenser,  the  car 
bonic  anhydride  is  diverted  by  means  of  the  three-way 
cock  P  through  the  funnel  so  as  to  remove  the  air  from 

1  Gattermann,  B.  23,  1222.  2  Gattermann,  foe.  cit. 

3  R.  Clauser,  B.  34  (1901),  891. 


DETERMINATION   OF   THE    DIAZO   GROUP,  ETC.  133 

its  lower  part.  The  bulbs,  filled  with  potassium  hy- 
droxide solution  (2  13)  are  then  attached,  and,  if  the  air 
has  been  completely  expelled,  4-5  times  the  theoreti- 


FIG.  17. 

cal  quantity  of  phenylhydrazine,  dissolved  in  concen- 
trated acetic  acid  (30-40  cc),  is  placed  in  the  funnel 
and  the  flask  gently  warmed.  By  means  of  the  cock 
P  sufficient  pressure  may  be  obtained  in  the  funnel  for 
its  contents  to  flow  into  the  flask.  The  reaction  usually 
requires  10  minutes  for  completion;  but  in  the  case  of 


134  RADICLES   IN    CARBON   COMPOUNDS. 

substances  sparingly  soluble  in  acetic  acid,  such  as  a^ 
nitroso-^-naphthol,  the  heating  is  continued  for  30 
minutes  or  more.  The  nitrogen  collected  in  the  absorb- 
tion  apparatus  by  the  stream  of  carbonic  anhydride, is 
transferred  to  a  measuring  vessel,  and  allowed  to  stand 
over  concentrated  potassium  hydroxide  solution  con- 
taining a  few  drops  of  benzene  (vide  p.  77).  The  results 
are  calculated  by  means  of  the  formula 

_  3000.^V. (b  —  co]     _  K.V(£  -co) 
=  760. 28.  (i  +  rt)g  =  =  ~g.(\  +  arf)' 

P  =  per  cent  of  nitroso  groups  in  the  substance ;  V 
the  cc  nitrogen  obtained;  GO  =the  sum  of  the  tension 
of  water  and  benzene  at  the  temperature  /;  and  g  the 

•5QQQ      Q 

grams  of  substance  taken.    K  is  the  constant  —^— 

760  +  28' 

where  S  =  weight  of  I  cc  nitrogen  at  NTP.  The 
results  are  usually  accurate  to  0.5  per  cent  of  P.  The 
method  has  not  yet  been  tested  with  complex  com- 
pounds such  as  nitrosamines,  polynitroso-,  and  iso- 
nitroso-derivatives  and  esters  of  nitrous  acid.  Cf.  p.  182. 

DETERMINATION  OF  THE  IODOSO-  (IO) 
AND  IODOXY-  (IO2)  GROUPS. 

lodoso-  and  iodoxy-compounds  in  presence  of  glacial 
acetic,  of  hydrochloric  acid,  or  of  dilute  sulphuric  acid, 
liberate  from  potassium  iodide  an  amount  of  iodine 
equivalent  to  their  content  of  oxygen ;  one  molecule  of 
the  former  therefore  liberates  two,  and  of  the  latter 
four  atoms  of  iodine.  For  the  determination,  the  sub- 
stance is  heated  on  the  water-bath  during  four  hours 
with  acidified  potassium  iodide  solution  in  a  sealed  tube 


DETERMINATION    OF    THE    DIAZO    GROUP,  ETC.   13$ 

from  which  the  air  has  been  expelled  by  carbonic 
anhydride.1  The  compound  may  also  be  digested  on 
the  water-bath  with  concentrated  potassium  iodide 
solution,  glacial  acetic  acid,  in  fairly  large  quantity, 
and  dilute  sulphuric  acid.*  When  the  reaction  is  com- 
pleted the  liquid  is  titrated  with  N/IO  sodium  thiosul- 
phate  solution;  no  indicator  is  required.  Whenever 
hydrochloric  acid  or  sulphuric  acid  has  been  employed 
in  the  reduction  the  fodide,  which  is  produced,  always 
retains  some  iodine  in  solution,  hence,  during  the 
titration,  it  is  necessary  to  warm  and  shake  the 
liquid  until  this  has  all  been  acted  upon  by  the 
thiosulphate.  The  oxygen  percentage  content  of  the 
iodoso-  and  iodoxy-compounds  is  given  by  the  formula 

O.8.£.IOO  C  , 

O  =  -  —  0.08-,  where  s  is  the  weight  of  the 

i  coos  s 

compound  taken  and  c  the  number  of  cc  of  N/io  sodium 
thiosdlphate  employed. 

DETERMINATION  OF  THE  PEROXIDE  GROUP 

r/9 


(c/YY 
\  \o/ 


The  oxygen  of  the  acyl  superoxides  may  be  deter- 
mined by  means  of  stannous  chloride  in  acid  solution.3 
A  known  quantity  of  the  peroxide  is  heated,  during 
about  five  minutes,  in  an  atmosphere  of  carbonic 
anhydride,  with  a  measured  volume  of  a  titrated,  acidi- 

1  V.  Meyer  and  Wr.chter,  B.  25,  2632.      P.  Askenasy  and  V.  Meyert 
Ibid.  26,  1355,  et  seq. 

2  Willgerodt,  Ibid.  25,  3495,  et  seq. 

3  Pechmann  and  Vanino,  Ibid.  27,  1512. 


136  RADICLES   IN    CARBON    COMPOUNDS. 

fied  stannous  chloride  solution.  When  the  liquid  is 
clear, the  remaining  stannous  chloride  is  determined  by 
means  of  N/io  iodine  solution.  The  substance  may 
also  be  treated  with  glacial  acetic  acid  and  potassium 
iodide  solution  until  a  clear  liquid  is  obtained  and 
the  liberated  iodine  titrated  with  sodium  thiosulphate. 
The  results  should  be  corrected  by  means  of  a  blank 
experiment.1 

THE  IODINE  NUMBER.2 

This  value  expresses  the  quantity  of  iodine  absorbed 
by  one  hundred  parts  of  the  substance,  usually  a  fat  or 
higher  aliphatic  acid.  The  acids  of  this  series,  such 
as  oleic  acid,  ricinoleic  acid,  linoleic  acid,  and  linolenic 
acid,  as  well  as  their  glycerides,  absorb,  the  first  two, 
the  others  four  and  six  atoms  of  iodine,  bromine,  or 
chlorine  respectively,  whilst  the  corresponding  saturated 
compounds,  under  similar  circumstances,  are  scarcely 
affected.  The  reaction  is  carried  out  at  the  ordinary 
temperature,  the  substance  being  mixed  with  alcoholic 
iodine  and  mercuric  chloride  solutions.3  The  organic 
products  are  chloro-iodine  additive  compounds,  some 
of  which  have  been  isolated  and  characterized.4  The 

1  A.  Baeyer  and  O.  Villiger,  B.  34  (1901),  765. 

2  Benedikt,  "Analyse  d.  Fette  und  Wachsarten,"  III.  Edition,  p.  148. 
Allen,  "  Commercial  Organic  Analysis,"  vol.  II,  3d  Edition.     J.  Lewko- 
witsch,    "Chemical  Analysis  of  Oils,   Fats,  and  Waxes"    (1902),  and 
"Laboratory   Companion   to  Fats  and   Oils  Industries"   (1901).     The 
former  work  deals  chiefly  with  methods,  the  latter  with   "constants." 
E.  Hopkins,  "  Oil  Chemist's  Handbook  "  (1900),  is  smaller  and  contains 
data  and  methods. 

3  Hubl,  Dingl.  253,  28  r 

4  R.  Henriques  and  H.  Kiinne,  B.  32,  380. 


DETERMINATION    OF   THE    DIAZO    GROUP,  ETC.   137 

method  is  extensively  employed  in  the  technical  in- 
vestigation of  fats,  oils,  waxes,  resins,  ethereal  oils, 
caoutchouc,  etc.,  and  is  sometimes  useful  for  scientific 
purposes,  hence  a  brief  description  of  the  details  of 
analysis  is  given  here. 

Reagents. 

(1)  Iodine  Solution.      Iodine   (25   grams),  and  mer- 
curic   chloride   (30   grams)  are  separately  dissolved   in 
95  per  cent  alcohol  (500  cc),  free  from  fusel  oil.      The 
mercuric  chloride  solution  is  filtered,  if  necessary,  and 
the  liquids  mixed.      The  mixing  must  precede  the  use 
of  the  solution  by  6-12   hours  as,  during  this  period, 
the   titre   rapidly  changes.      Instead   of  this  a  solution 
of   iodine    monochloride,   or   iodine    bromide    in    pure 
glacial    acetic    acid   may  be   used ;   with   care  it  gives 
results   identical  with  the   alcoholic  solution  described 
above,  and  is  greatly  superior  to  it  in  stability.1 

(2)  Sodium  Thiosulphate  Solution.     The  crystallized 
salt  (24  grams)  is  dissolved  in  water,  and  diluted  to  one 
liter.      It   is   standardized    in    the  following   manner:2 
Potassium  bichromate  (3.8740  grams)   is  dissolved  in 
water,    diluted    to    one   liter,    and    20    cc   of  the  liquid 
transferred  to  a  stoppered  bottle  containing   10  cc  of 
potassium  iodide  solution   (10  per  cent),  and   5  cc  hy- 
drochloric acid ;   the   liberated  iodine  is  then  titrated  in 
the  ordinary  manner  by  means  of  sodium  thiosulphate, 
starch  being  used  as  indicator  ;  I  cc  of  the  above  bichro- 
mate solution  liberates  o.Oi  gram  of  iodine. 


1 J.  J.   A.   Wijs,   B.    31   (1898),    750.     J.    Lewkowitsch,   Analyst,   24 

(1899),  257. 


138  RADICLES    IN    CARBON    COMPOUNDS. 

(3)  Chloroform.      Its  purity  is  determined  by  a  blank 
experiment. 

(4)  Potassium  Iodide  Solution.      The  salt  is  dissolved 
in  ten  parts  of  water. 

(5)  Starch   Solution.     This   must  be   clear   and  re- 
cently prepared. 

Method  of  Analysis. 

The  substance  (0.15-1.0  gram)  is  mixed  with  chlo- 
roform (about  10  cc)  in  a  500-800  cc  flask  provided 
with  a  well-fitting  glass-stopper.  When  the  com- 
pound has  dissolved, the  iodine  solution  (25  cc)  is  added 
by  means  of  a  pipette  which  must  be  manipulated  so 
that  equal  quantities  are  delivered  in  each  experiment. 
The  flask  is  well  shaken,  and  more  chloroform  added 
if  needful ;  should  the  liquid  become  almost  colourless 
in  a  short  time  a  second  25  cc  of  iodine  solution  is 
added,  and  this  repeated,  if  necessary,  until,  after  the 
expiration  of  two  hours,  the  liquid  appears  dark  brown. 
The  mixture  is  now  allowed  to  remain  during  twelve 
hours  at  the  ordinary  temperature  in  the  dark ;  it  is 
then  thoroughly  mixed  with  at  least  20  cc  of  potassium 
iodide  solution  and  300-500  cc  of  water,  and  titrated 
with  the  sodium  thiosulphate  solution,  the  liquid  being 
constantly  agitated ;  when  only  a  faint  colour  is  visible 
in  both  the  aqueous  and  chloroform  solutions,  starch 
is  added  and  the  titration  completed.  The  production 
of  a  red  precipitate  of  mercuric  iodide,  on  the  addition 
of  water  before  the  titration,  indicates  that  too  little 
potassium  iodide  has  been  employed,  but  this  may  be 
corrected  by  the  immediate  addition  of  more.  A 


DETERMINATION   OF   THE    DIAZO   GROUP,  ETC.  139 

blank  experiment  must  always  be  made  with  25  cc  of 
the  iodine  solution,  under  exactly  the  same  conditions 
as  the  test,  and  its  titration  must  immediately  precede 
or  follow  that  of  the  actual  determination. 

Useful  information  is  sometimes  given  by  the  tere- 
benthene  number,1  and  the  acetyl  'value.2  Vide  also  p. 
184. 

1  J.  Klimont,  Ch.  Ztg.  (1894),  No.  35,  37.     Ch.  R.  (1894),  2,  2. 

2  J.  Lewkowitsch,  Analyst,  24  (1899),  319. 


APPENDIX. 


141 


METHODS  OF  ACETYLATION. 

PREPARATION    OF     ACETYL     DERIVATIVES.' 

Cf  p.  6  et  seq. 

Acetyl  derivatives  may  be  obtained  by  the  action  of 
acetyl  halides,  or  esters  of  acetic  acid  on  organomag- 
nesium  halides  (Grignard  reagent). 

Dry  sodium  dimethylbutanetricarboxylate,  when 
heated  with  acetic  anhydride,  eliminates  carbon  di- 
oxide and  water.1 

The  action  of  sulphuric  acid  in  promoting  acetyla- 
tion  by  means  of  acetic  anhydride  appears  to  depend  on 
the  formation  of  acetylsulphuric  acid,  CHsCOOSOsH, 
and  of  sulphoacetic'acid,  HOSO2CH2CO2H.2 

Acetic  anhydride  acetylates  many  i,  3-diketones;  in 
some  cases  the  product  has  the  acetyl  linked  to  carbon, 
in  others  to  oxygen.  Apparently  the  production  of 
the  former  compounds  is  due  to  the  presence  of  a  con- 
densing agent,  such  as  alkali  from  the  glass  vessels 
employed.3 

Ketones  and  the  esters  of  ketonic  acids  often  react 
without  difficulty  when  treated  with  an  acid  chloride 
and  a  tertiary  base,  such  as  pyridine.  The  resulting 

1  William  Henry  Perkin,  Jr.,  and  Jocelyn  Field  Thorpe,  Journ.  Chem. 
Soc.,  85,  130  (1904). 

2  Otto  Stillich,  B.  38,  1241  (1905). 

3  W.  Dieckmann  and  Richard  Stein,  B.  37,  3370  (1904). 


144  APPENDIX. 

O-acyl  compounds  change  rather  easily  into  C-acyl 
derivatives.  Incorrect  conclusions  regarding  the  con- 
stitution of  a  compound  may,  therefore,  be  drawn 
unless  the  results  of  acylation  experiments  are  duly 
controlled.  l 

ISOLATION   OF    ACETYL    DERIVATIVES. 
Cf.  p.  10. 

The  acetyl  derivative  of  leucobenzophloroglucinol 
trimethyl  ether  (2,  4,  6-trimethoxybenzhydrol)  is  so 
unstable  that  it  is  converted  into  the  tetramethyl  or 
trimethylmonoethyl  ether  by  recrystallization  from 
methyl  or  ethyl  alcohol,  respectively.2 

DETERMINATION   OF   ACETYL   GROUPS. 
Cf.  p.  n. 

Some  acetyl  compounds  may  be  hydrolysed  by  dis- 
solving the  substance  (i  gram)  in  acetic  acid  (15  cc.) 
and  boiling  with  sulphuric  acid  (about  2  cc.).  The 
resulting  hydroxyl  derivative  (phenol)  is  precipitated 
with  water,  collected  and  weighed.3  In  certain  cases  the 
reaction  takes  place  at  the  ordinary  temperature.4  To 
avoid  sulphonation  the  sulphuric  acid  may  be  replaced 
by  hydrochloric  acid.5  Concentrated  alcoholic  solu- 
tion of  potassium  acetate  may  also  be  used  as  the 
hydrolytic  agent  in  cases  where  alkali  decomposes  the 

1  Cf.  L.  Claisen  and  E.  Haase,  B.  36,  3674  (1903). 

2  St.  v.  Kostanecki  and  v.  Lampe,  B.  39,  4020  (1906). 

3  Arthur  George  Perkin,  Journ.  Chem.  Soc.,  69,  210  (1896). 

4  Ibid.,  73,  1034(1898). 

5  Ibid.,  75,  448  (1899). 


APPENDIX.  145 

hydroxyl    compound.     The    acetic    acid    is    evolved    as 
ethyl   acetate.1     The   following   method   gives   good   re- 
sults   in    many    cases,    especially    with-  derivatives    of 
phenolic   coloring   matters.2    The   tubulure   of   a   small 
retort   is  bent   from  the   center   at   a  slight   angle   and 
into  the  neck  a  small  tap  funnel  is  fitted.     The  sub- 
stance (about  0.5  gram),  alcohol  (30  cc.)  and  sulphuric 
acid   (2   cc.)    are  placed  in  the  retort  and  the  mixture 
gently  distilled  until  about  two-thirds  have  passed  over. 
Fresh  alcohol  (20  cc.)  is  now  added  and  the  distillation 
continued;   one  or  two  more  portions  of  alcohol  (20  cc.) 
being  run  in  if  necessary.     The  combined  distillate  is 
collected  in  a  flask  containing   iN  alcoholic  potassium 
hydroxide    solution    (20    cc.).     The    flask    is    connected 
with  a  reflux  condenser  and  heated  on  the  water-bath 
for  a  few  minutes,  after  which   the   product  is  diluted 
with  a  little .  water  t and  titrated  with  iN  sulphuric  acid. 
When  the  quantity  of  substance  available  is  very  limited 
more  dilute  acid  is  used  for  the  titration.     The  distilla- 
tion usually  occupies  about  three-quarters  of  an  hour. 
The   whole    operation    should    not    require    more    than 
an    hour    and    a    quarter    and    less    time    is    usually 
sufficient.     In  most  cases  the  phenolic  compounds  can 
be  recovered  in  a  state  of  purity  from  the  residue  in 
the  retort. 

The  following  method  of  hydrolysing  acetyl  deriva- 
tions is  simple  and  sufficiently  accurate  for  general 
purposes:  The  substance  (about  0.5  gram)  is  distilled 
with  alcohol  (30  cc.)  and  sulphuric  acid  (2  cc.),  a  little 


1  Arthur  George  Perkin,  Journ.  Chem.  Soc.,  75,  433  (1899), 

2  Ibid.,  87,  107  (1905). 


146  APPENDIX. 

more  alcohol  being  added  occasionally.  The  distillate 
is  collected  in  a  known  volume  of  standard  alcoholic 
potassium  hydroxide  solution,  which  is  subsequently 
boiled  in  order  to  hydrolyse  any  ethyl  acetate  and  is 
finally  titrated  with  sulphuric  acid.  With  acetanilide 
and  its  homologues  4  cc.  of  sulphuric  acid  are  em- 
ployed.1 

Many  acetyl  derivatives  may  be  hydrolysed  by  heat- 
ing the  substances  (0.2-0.4  gram)  with  benzenesulphonic 
acid  or  a-  or  /?-naphthalenesulphonic  acids,  in  a  current 
of  steam,  the  distillate  being  titrated  by  barium  hydroxide 
in  presence  of  phenolphthalein.  The  acids  are  used  in 
about  10  per  cent  solution  and  they  must  be  freed  from 
volatile  matter  by  the  steam  distillation  of  their  barium 
salts.  The  hydrolysis  usually  requires  2-6  hours  and 
the  steam  and  heat  should  be  regulated  so  that  the 
volume  of  acid  solution  remains  practically  constant. 
The  rate  of  distillation  varies  from  about  150-500  cc. 
per  hour  and  the  usual  precautions  must  be  taken  to 
avoid  the  mechanical  transfer  of  drops  of  acid  liquid. 
The  hydrolysis  of  N-acetyl  compounds  proceeds  more 
slowly  than  that  of  0-derivatives.  The  advantages  of 
the  method  are  that  there  is  no  danger  of  producing 
sulphur  dioxide  and  that  the  acids  employed  are  stronger 
than  phosphoric  acid.2 

The  following  method  of  hydrolysis  by  means  of 
alkali  gives  more  accurate  results  with  acetyl  derivatives 
than  that  described  on  p.  12.  The  substance  (o^.-o.y 

1  Arthur  George  Perkin,  Proc.  Chem.  Soc.  (London),  20,  171  (1904.) 

2  John  Joseph  Sudborough  and  Walter  Thomas,  Journ.  Chem.  Soc., 
87,  1752  (1905). 


APPENDIX.  147 

gram)  is  mixed  with  pure  sodium  hydroxide  (5  grams) 
and  methyl  alcohol  (50  cc.)  that  has  been  distilled  over 
potassium  carbonate.  The  mixture  is  heated  for  about 
an  hour  on  the  water-bath,  in  a  reflux  apparatus.  After 
being  cooled,  phosphoric  acid  (d  =1.104,  5°  cc-)  is  added 
and  the  liquid  is  distilled  quickly  in  a  current  of  steam, 
generated  from  water  containing  calcium  hydroxide.  The 
distillate  is  titrated  with  o.iN  barium  hydroxide  solution, 
in  presence  of  phenolphthalein.  When  about  150  cc.  of 
the  distillate  requires  only  1-2  drops  of  the  hydroxide  for 
neutralization  the  determination  is  finished.  Absorption 
of  carbon  dioxide  is  avoided  as  far  as  possible  by  working 
rapidly.  It  is  not  advisable  to  use  ethyl  alcohol  for  the 
hydrolysis  because  of  the  error  introduced  by  its  oxidation 
to  acetic  acid  during  the  heating  with  alkali. 

The  process  described  above  is  also  applicable  to  the 
determination  of  benzoyl  groups,  and  is  superior  in  some 
respects  to  the  metKod  given  on  p.  2 p.1 


BENZOYL  DERIVATIVES.     Cf.  p.  21. 

PREPARATION    OF    BENZOYL   DERIVATIVES. 

Barium  hydroxide  has  been  found  to  offer  advantages 
over  sodium  hydroxide  in  the  benzoylation  of  the  hydro- 
lytic  products  of  proteids.2  Vide  p.  25. 

Methyl  camphorcarboxylate  can  be  benzoylated  by 
benzoyl  chloride  and  finely  divided  sodium,  or  the  chloride 

1  Richard  Meyer  and  Ernst  Hartmann,  B.  38,  3956  (1905). 

2  Alexandra  Etard  and  A.  Vila,  C.  r.,  135,  698  (1902). 


T48  APPENDIX. 

is  allowed  to  react  with  the  halide  magnesium  derivative 
of  the  carboxylate  (Grignard  reagent).1 

Acylation  of  hydroxyl  derivatives  in  presence  of  pyri- 
dine  or  quinoline  may  lead  to  the  production  of  C-acyl 
compounds,  if  the  primary  addition  compound  is  not 
stable  in  the  presence  of  these  tertiary  bases.2 

Certain  oximes  have  been  observed  to  rearrange  to 
amides  by  the  action  of  various  acid  chlorides  which 
appear  to  act  essentially  as  catalytic  agents.3 


ANALYSIS  OF  BENZOYL  DERIVATIVES. 

Cf.  p.  28. 

A  new  method  for  the  hydrolysis  of  benzoyl  derivatives 
is  described  in  connection  with  the  analysis  of  acetyl 
compounds.  Vide  p.  147. 


ACYLATION  BY  MEANS  OF  OTHER  ACID 
RADICLES.     Cf.  p.  30. 

Pyromucyl  chloride  (a-furfuranecarboxyl  chloride)  is 
prepared  by  heating  pyromucic  acid  with  thionyl  chloride 
(5  parts)  on  the  water-bath  and  fractionating  the  residue. 
The  yield  is  quantitative.  The  chloride  reacts  readily 
with  hydroxyl  and  amino  compounds,  under  conditions 
similar  to  those  employed  in  the  case  of  benzoyl  chloride. 
As  a  rule  the  products  are  somewhat  more  soluble  than 


1  J.  W.  Briihl,  B.  36,  4272  (1903). 

2  A.  Michael  and  O.  Eckstein,  B.  38,  50  (1905). 

3  E.  Beckmann,  B.  37,  4136  (1904). 


APPENDIX.  149 

the  corresponding  benzoyl  derivatives,  but  they  crystallize 

readily.1 

• 

ALKYLATION  OF  HYDROXYL  GROUPS. 

Cf.  p.  31. 

Methyl  and  ethyl  p-toluenesulphonate ,  from  the  chloride 
and  the  respective  alcohol,  may  be  used  for  alkylation 
purposes.  With  the  naphthols  it  is  employed  in  the 
presence  of  alkali,  but  certain  acridine  and  phenazine 
derivatives  react  directly,  in  nitrobenzene  solution.2 

A  number  of  sugars  3  have  been  alkylated  by  treatment 
with  methyl  iodide  and  dry  silver  oxide.  The  method  is 
also  applicable  to  the  esters  of  hydroxy  acids,4  to  amides 
and  to  certain  other  classes  of  compounds.5 

Substances  such  a  vanillin,  which  form  sparingly 
soluble  sodium  derivatives,  or  which  yield  products 
sensitive  to  alkali,'  may  be  alkylated  by  dissolving 
them  in  warm  dimethyl  sulphate  (0.9  mol.)  and  adding, 
drop  by  drop,  aqueous  potassium  hydroxide  1:2  in 
equivalent  proportion.  The  mixture  is  well  shaken  and, 
finally,  enough  alkali  is  added  to  give  a  permanent  reac- 
tion. The  product  is  extracted  with  ether.6 


1  Erich  Baum,  B.  37,  2949  (1904). 

2  Fritz  Ullmann  and  P.  Winner,  Ann.  327,  120  (1903). 

3  Thomas  Purdie  and  James  C.  Irvine,  Journ.  Chem.  Soc.,  83,  1021 
(1903);    James  C.  Irvine  and  Adam  Cameron,  Ibid.,  85,   1071    (1904). 

4  Thomas   Purdie   and   William    Pitkeathly,    Ibid.,    75,    153    (1899); 
Thomas  Purdie  and  James  C.  Irvine,  Ibid.,  75,  483   (1899);    79,  957 
(1901);   Alex.  McKenzie,  Ibid.,  75,  753  (1899). 

5  George  Druce  Lander,  Ibid.,  77,  729  (1900);    79,  690  (1901);    81, 
591  (1902);   83,  4i4  (i903)- 

B  Herman  Decker  and  Otto  Koch,  B.  40,  4794  (1907). 


150  APPENDIX. 

PREPARATION      AND      REACTIONS      OF      DI- 
PHENYLCARBAMYL  CHLORIDE.     Cf.  p.  34. 

Diphenylcarbamyl  chloride,  (C6H5)2NCOCL,  does  not 
react  with  carbinols,  but  with  all  classes  of  phenols  it 
yields  urethanes,  ROCON(C6H5)2,  quantitatively.  These 
compounds  crystallize  very  readily.  With  phenolcarboxy- 
lic  acids  the  yield  is  much  smaller.  The  chloride  is  em- 
ployed in  presence  of  pyridine,  with  which  it  probably 
forms  an  additive  product,  C5H5NC1CON(C6H5)2.  The 
phenol  is  heated  at  100°,  in  a  reflux  apparatus,  for  an 
hour,  with  four  times  its  weight  of  pyridine  and  diphenyl 
carbamyl  chloride  (i  mol).  The  product  is  poured  into 
water  which  is  well  stirred;  the  tarry  crystals  are  dried 
roughly  and  purified  by  means  of  ligroin  or  alcohol.1 

The  use  of  Acetylhydroxamic  chloride,  CH3CC1:NOH 
as  a  reagent  for  phenols  2  is  described  on  p.  159. 

ACTION     OF     PHENYLCARBIMIDE     (PHENYL- 
ISOCYANATE).     Cf.  p.  35. 

Many  of  the  sugars  and  polyhydric  alcohols  react  with 
phenykarbimide  (phenylisocyanate)  in  piperidine  solution. 
In  some  cases  the  action  proceeds  quantitatively.  The 
products  are  usually  amorphous  or  microcrystalline  and 
have  no  sharp  melting  point.3 

The  interaction  of  phenykarbimide  and  enolic  1.3- 
diketones  is  stated  to  take  place  only  in  the  presence 


1  J.  Herzog,  B.  40,  1831  (1907). 

2  Heinrich  Wieland,  Ibid.,  40,  1676  (1907). 

8  Leon  Maquenne  and  W.  Godwin,  C.  r.  138,  633  (1904). 


APPENDIX.  151 

of  a  condensing  agent,  such  as  alkali,  which  may  even  be 
derived  from  the  glass  vessels  employed.1 

Certain  hydroxy  derivatives  of  naphthalene  com- 
bine with  hydrazine  forming  hydrazides,  such  as 
CioH6(NHNH2)2.2 

Hydroxyl  compounds  containing  a  basic  group  when 
treated  with  acyl  chlorides,  usually  form  Af-acyl  deriva- 
tives, the  hydroxyl  being  only  attacked  subsequently. 
Provided  that  the  compound  is  acidic  and  that  the  basic 
properties  are  not  too  pronounced,  it  is  possible  to  prepare 
O-acyl  derivatives  by  the  pyridine  method,  if  a  large 
excess  of  acyl  chloride  is  used.  Under  these  conditions 
the  O-acyl  derivatives  are  stable,  whereas  Ar-acyl  com- 
pounds are  converted  into  diacylated  products.3 

The  hydroxyl  group  of  a  number  of  polyhydric  alcohols 
is  replaced  completely  by  bromine  if  the  alcohol  is  first 
converted  into  the  acetate,  and  the  latter  then  heated  at 
150°  with  glacial' acetic  acid,  which  has  been  saturated 
with  hydrogen  bromide  at  o°.  The  method  is  not  ap- 
plicable to  phenols.  At  the  ordinary  temperature,  in 
presence  of  benzene,  phosphorus  pentabromide  converts 
pyrogallol  into  a  dibrompyrogallol  and  phloroglucino, 
into  tribromphloroglucinol.4 


1  W.  Dieckmann  and  Richard  Stein,  B.  37,  3370  (1904). 

2  Hartwig  Franzen,  B.  58,  268  (1905). 

3  Karl  Auwers,  B.  37,  3899  (1904). 

4  William   Henry    Perkin,    Jr.,    and    John    Lionel    Simonsen,    Journ. 
Chem.  Soc.,  87,  855  (1905). 


152  APPENDIX. 

DETERMINATION  OF  HYDROXYL  BY  MEANS 
OF  ALKYLMAGNESIUM  HALYDES  (GRIG- 
NARD  REAGENT).  Cf.  p.  37. 

The  following  method  gives  quantitative  results  with 
many  hydroxyl  compounds:  it  is  an  improved  modi- 
fication of  the  process  devised  by  Tschugaeff.  Methyl- 
magnesium  iodide  (Grignard's  reagent)  is  prepared  by 
mixing  magnesium  turnings  (6.09  grams)  with  dry  ether 
(100  cc.  and  methyl  iodide  35.5  grams),  dissolved  in 
dry  ether  (20  cc.).  The  mixture  is  warmed  gently  to 
start  the  reaction,  which  is  then  allowed  to  proceed  at  the 
ordinary  temperature,  and  is  finally  completed  by  heating 
for  half  an  hour.  When  cold  the  clear  liquid  is  decanted 
from  undissolved  metal  and  made  up  to  200  cc.  with  pure 
amyl  ether.  The  solution  will  keep  if  protected  from 
moisture,  oxygen  and  carbon  dioxide.  Before  use  the 
amyl  ether  is  dried  over  calcium  chloride,  boiled  for 
several  hours  with  sodium,  treated  with  5  cc.  of  the 
methylmagnesium  iodide  solution,  again  boiled  with 
sodium,  allowed  to  remain  for  several  hours  in  contact 
with  phosphoric  anhydride  and  finally  distilled.  The 
analysis  is  conducted  in  a  stout  flask  of  200  cc.  capacity, 
fitted  with  a  doubly-bored  rubber  stopper.  In  one  hole 
there  is  a  short  tube  connected  by  means  of  thick-walled 
rubber  tubing  to  a  Lunge  nitrometer  or  Hempel  burette, 
filled  with  dry  mercury.  Through  the  second  hole  in  the 
stopper  there  is  placed  a  tube  passing  almost  to  the 
bottom  of  the  flask  and  fitted  at  its  upper  end  with  a 
stopcock.  Amyl  ether  (10-20  cc.) ,  dried  as  described  above, 
is  placed  in  the  flask  together  with  the  substance  under 


APPENDIX.  153 

examination  (0.10-0.25  gram).  The  methylmagnesium 
iodide  solution  (about  15  cc.),  contained  in  a  small  tube, 
is  lowered  into  the  flask,  care  being  taken*  to  retain  the 
tube  in  a  vertical  position.  The  air  in  the  flask  is  now 
displaced  by  dry  nitrogen,  the  burette  attached  and  the 
apparatus  left  for  2-4  hours  to  attain  a  constant  tempera- 
ture. At  the  end  of  this  period  the  height  of  the  mercury, 
the  temperature  and  the  pressure  are  noted  and  the  two 
solutions  are  mixed  and  shaken  vigorously.  The  level  of 
the  mercury  is  adjusted  and  the  volume  read  off  with  the 
usual  precautions;  OH  =  CH4.  In  the  case  of  all  the 
compounds  experimented  with  the  results  were  normal 
except  that  O-nitrophenol,  gave  almost  double  the  cal- 
culated volume  of  gas.  Tautomeric  diketones  appear  to 
be  changed  largely  to  the  enolic  modification  by  the 
methylmagnesium  iodide.1 

Separation  of  phenols. — An  ingenuous  method  has  been 
described  for  the  separation  of  monohydric  from  poly- 
hydric  phenols.2  The  substance  is  dissolved  in  three 
times  its  volume  of  benzene,  or  of  carbon  tetrachloride  if 
catechol  is  present,  and  the  solution  shaken  with  two 
volumes  of  water.  The  monohydric  phenols  and  phenol 
ethers  remain  in  the  benzene,  the  others  pass  into  the 
water.  After  removal  of  the  benzene,  the  monohydric 
phenols  are  separated  by  fractional  distillation  in  steam. 
The  polyhydric  compounds  are  differentiated  by  their 
varying  behavior  with  solvents  or  with  lead  acetate, 
bromine,  quinone,  etc. 


1  Harold  Hibbert  and  John  Joseph  Sudborough,  Journ.  Chem.  Soc., 

85,  933  (i9°4). 

2  G.  Heinrich  Behrens,  Z.  anal.  42,  141  (1903). 


154 


APPENDIX. 


Some  methods  for  the  determination  of  a  few  of  the 
more  important  individual  hydroxy  compounds  are  de- 
scribed in  the  MISCELLANEOUS  SECTION,  p.  186  et  seq. 


DETERMINATION   OF   METHOXYL,   — OCH3. 

Cf.  p.  38. 

MODIFICATION    OF    ZIESEL's    METHOD.       Cf.  p.  46. 

The  simplified  apparatus  shown  in  Fig.  18  has  proved 
to  be  very  efficient'.1     The  neck  of  the  distillation  flask  is 


8  inches  in  length.  The  substance  (0.3-0.35  gram)  is 
weighed  in  a  piece  of  very  small  test-tube  and  pushed 
into  the  acid  (b.  p.  126°)  by  the  carbon  dioxide  delivery 

1  W.  H.  Perkin,  Journ.  Chem.  Soc.,  83,  1367  (1903). 


APPENDIX.  155 

tube,  which  is  held  in  position  by  the  rubber  stopper  A. 
About  15  cc.  of  acid  are  used;  in  some  cases  a  little  acetic 
anhydride  is  added.  Heat  is  applied  by  means  of  a 
glycerol  bath  in  the  ordinary  manner,  care  being  taken 
that  the  acid  shall  boil  gently  but  shall  not  distil  into  the 
absorption  flasks.  As  a  rule  one  hour  suffices  to  com- 
plete the  reaction;  at  the  end  of  this  time  the  flasks  are 
disconnected  and  a  U-tube,  containing  a  few  cc.  of  silver 
nitrate  solution,  is  attached.  After  20  minutes  further 
heating,  if  no  precipitate  forms,  the  boiling  is  stopped, 
otherwise  the  silver  precipitate  is  added  to  that  in  the 
flasks,  the  U-tube  is  refilled  and  the  heating  continued  for 
another  20  minutes  and  so  on  until  the  decomposition  is 
complete.  The  tube  C  touches  the  surface  of  the  liquid 
in  the  first  absorption  flask  B,  and  dips  below  that  in  the 
second  one.  Carbon  dioxide  is  passed  at  the  rate  of  3  or 
4  bubbles  in  2  seconds.  At  the  end  of  the  experiment 
the  contents  of  the  absorption  flasks  are  added  to  50  cc. 
of  boiling  water  which  is  acidified  with  nitric  acid,  a  little 
porous  porcelain  being  added  to  prevent  bumping.  The 
boiling  is  continued  until  most  of  the  alcohol  has  volatil- 
ized; the  liquid  is  then  allowed  to  remain  for  an  hour  at 
the  ordinary  temperature  and  the  precipitate  collected  on 
a  tared  filter.  The  apparatus  can  also  be  employed  for 
the  determination  of  ethoxyl,  but  the  results,  as  usual,  are 
often  somewhat  low. 

Another  simplified  apparatus  for  the  Zeisel  method  is 
shown  in  Fig.  19  and  is  made  by  the  Vereinigte  Fabriken 
fiir  Laboratoriumsbedarf,  Berlin,  or  the  Kny-Scheerer 
Co.,  New  York.  Red  phosphorus  (0.5  gram)  is  well 
boiled  with  water  and  then  incorporated  with  sufficient 
water  to  fill  each  of  the  washing  devices  A,  A  one-half 


156 


APPENDIX. 


cm.  above  the  lower  edge  of  the  inner  bulb.  The  water 
for  the  condenser  is  supplied  from  a  heated  wash  bottle, 
one  tube  of  which  is  connected  with  the  cold  water  faucet, 

the  opening  or  closing  of 
this  regulates  the  temper- 
ature.1 

It  is  found  that  certain 
dyes  of  the  nitrosophenol 
series  only  eliminate  all 
their  ethoxyl  when  boiled 
with  saturated  hydriodic 
acid  during  3-4  hours.2 

The  following  further 
simplification  of  Zeisel's 
method  gives  good  results 
with  compounds  which  are 
are  not  too  volatile.  The 
round-bottomed  flask  A , 
Fig.  20,  has  a  capacity  of 
150-200  cc.,  and  is  fitted 
with  a  fractionating  column 
By  containing  seven  or  eight  bulbs.  Hydriodic  acid  (sp. 
gr.  =  1.68-1.70,  about  16  cc.)  is  poured  into  the  flask  A, 
the  column  is  set  in  place,  the  liquid  heated  for  10  minutes 
at  about  130°,  in  the  glycerol  bath  C.  A  slow  current 
of  carbon  dioxide  is  passed  through  the  tube,  the  lower 
end  of  which  should  be  1.5-2  cm.  above  the  surface  of 
liquid.  In  this  manner  any  phosphine  or  other  impurity 
is  removed.  The  .acid  is  now  cooled,  the  substance  under 


FIG.  19. 


1  Herman  Decker,  B.   36,  2895   (1903). 

*H.  Decker  and  B.  Solonina,  B.  35,  3217  (1902);  36,  2886  (1903). 


APPENDIX. 


157 


examination  (0.2-0.3  §ram)  ^s  added  and  the  apparatus 
connected  together.  The  absorption  flasks  are  filled  ex- 
actly according  to  Zeisel's  directions,  Vide  p.  39.  For 
methoxyl  the  temperature  of  the  bath  should  be  130°,  the 
time  of  heating  not  more  than  45  minutes,  while  at  the 
top  of  the  column  the  temperature  should  be  2o°-25°. 
Ethoxyl  is  determined  in  a 
similar  manner,  except  that 
the  temperatures  are  140° 
and  about  27°,  respectively, 
and  the  current  of  carbon 
dioxide  is  somewhat  more 
rapid.  The  omission  of  the 
phosphorus  is  found  to  be 
of  decided  advantage.1 

Another  simplification  of  °~( 
Zeisel's  method  has  been 
described  together  with  a 
rapid  process  for  the  collec- 
tion and  drying  of  the  silver 
iodide.  In  place  of  red 
phosphorus  for  the  absorp- 
tion of  hydriodic  acid, 
sodium  antimonyl  tartrate 
is  employed;  it  serves  to  indicate  the  presence  of  sulphur 
in  the  substance  under  examination,  but  the  method 
cannot  be  applied  to  compounds  containing  this  element.2 

When  potassium  arsenate  is  used  to  absorb  traces  of 
hydriodic  acid   (cf.  p.  46)  its  concentration  should  not 


FIG.  20. 


1  J.  G.  Hewitt  and  G.  S.  Moore,  Journ.  Chem.  Soc.,  81,  318  (1902). 

2  Milan  J.  Stritar,  Z.  anal.  42,  579  (1903). 


158  APPENDIX. 

exceed  2  per  cent,  otherwise  crystals  of  KI.As4O(j  may 
form.  Hydriodic  acid  free  from  phosphine  may  be 
obtained  by  boiling  iodine  with  formic  acid,  in  a  reflux 
apparatus.1 

Compounds  containing  sulphur,  when  treated  by 
Zeisel's  method,  or  by  any  of  its  modifications,  eliminate 
hydrogen  sulphide.  A  part  of  this  is  converted  into 
silver  sulphide,  and  a  portion  combines  with  methyl 
iodide  forming  mercaptans.  Consequently,  even  when 
the  silver  precipitate  is  treated  with  hot  dilute  nitric  acid 
to  remove  sulphide,  the  results  are  always  too  low. 
Nevertheless,  the  method  has  been  found  useful  in  the 
case  of  some  sulphur  derivatives.2 

A  number  of  compounds  which  contain  the  groups 
CHsN  and  CO  in  the  ortho  position,  eliminate  methyl 
when  they  are  heated  with  aqueous  hydriodic  acid.3 

The  methylbetaines  of  quinolinic,  pyridine— 2,  3,  4- 
tricarboxylic,  papaverinic  and  pyropapaverinic  acids, 
derivatives  of  pyridine  containing  the  group,  — COCNCH3, 
and  methylanthranilic  acid  eliminate  part  of  the  AT-methyl 
when  heated  with  hydriodic  acid.  Papaveraldine  meth- 
iodide  evolves  little  if  any  methyl  iodide  under  these  con- 
ditions, and  none  at  all  is  obtained  from  sarcosine,  be- 
taine,  creatine,  creatinine,  and  methylaminoacetophe' 
none.4 


1  Wilhelm  Kropatscher,  M.  25,  583  (1904). 

*R.  Gnehm  and  F.  Kaufler,  B.  37,  2621  (1904). 

8Busch,  B.  35,  1565  (1902);  Goldschmidt,  M.  7,  485  (1886);  Decker, 
B.  36,  261  (1903);  G.  Goldschmiedt  and  O.  Honigschmid,  Ibid.  36, 
1850  (1903). 

*  Guido  Goldschmiedt  and  Otto  Honigschmid,  M.  24,  707  (1903). 


APPENDIX.  159 

DETERMINATION  OF  CARBOXYL. 

Cf.  p.  48. 

TITRATION  OF  ACIDS.      Cf.  p.  50. 

The  higher  aliphatic  acids,  such  as  oleic,  palmitic,  and 
stearic,  may  be  titrated  by  o.iN  sodium  hydroxide 
solution,  in  presence  of  phenolphthalein,  provided  that 
more  than  40  per  cent  of  the  total  volume  of  liquid 
consists  of  ethyl  or  methyl  alcohol;  with  amyl  alcohol 
10  per  cent  is  sufficient.1 

Certain  hydroxy  or  halogenated  aldehydes,  and  also 
some  diketones,  react  with  alkali  like  monobasic  acids, 
and  may  be  titrated  in  aqueous  or  alcoholic  solution. 
In  some  cases  the  end-point  depends  on  the  indicator 
employed,  such  as  helianthin  A,  phenolphthalein  or 
Poirrier's  blue.  The  simple  aliphatic  and  aromatic 
aldehydes  or  ketones  are  neutral.2 

ESTERIFICATION.       Cf.  p.  51. 

A  number  of  mixed  anhydrides  react  with  alcohol  in  a 
rather  peculiar  manner.  Thus  benzoic  ^-nitrobenzoic 
anhydride  and  benzoic  mesitylenecarboxylic  anhydride 
yield  benzoic  acid  together  with  ethyl  ^-nitrobenzoate 
and  ethyl  mesitylcarboxylate,  respectively,  whereas  ben- 
zoic cuminic  anhydride  forms  both  acids  and  both  esters 
in  considerable  quantity.3 


1  Aristides  Kanitz,  B.  36,  400  (1903). 

3  A.  Astruc  and  H.  Murco,  C.  r.  131,  943  (1900);  Hans  Meyer,  M.  24, 
832  (1903). 

3  Robert  Kahn,  B.  36,  2535  (1903). 


l6o  APPENDIX. 

As  shown  by  Dumas  and  Peligot,  in  1853,  esters  may 
be  prepared  by  the  interaction  of  dimethyl  sulphate  on 
aqueous  solutions  of  the  alkali  salts  of  organic  acids. 
The  action  is  more  energetic  than  that  of  alkyl  halides, 
and  the  preparation  may  be  carried  out  in  open  vessels.1 

Dimethyl  sulphate  gives  only  a  small  yield  of  methyl 
benzoate  when  shaken  or  heated  with  solutions  of  salts 
of  benzoic  acid,  but  the  production  of  methyl  ester  is 
quantitative  if  the  sulphate  is  heated  with  the  solid  salt, 
first  at  160°  and  finally  at  2O5°-2io°.  Both  the  methyl 
groups  of  the  sulphate  react  and  the  use  of  potassium 
benzoate  is  preferable  to  that  of  the  sodium  salt. 

The  results  with  acetates  are  similar  to  those  with 
benzoates.  Potassium  chloranilate  is  only  esterified  by 
heating  with  the  sulphate  at  100°.  Tetrachlorphthalaces 
and  naphthalates  react  either  in  the  solid  state  or  in  solu- 
tion, but  the  yield  of  ester  is  very  poor.2 


METHODS   FOR   THE   SEPARATION   OF   ACIDS. 

A  useful  method  for  the  characterization  of  the  aliphatic 
acids  consists  in  dissolving  the  substance  in  anhydrous 
ether,  adding  sodium  (i  atom)  and  then  chlorocetone 
(i  mol.).  The  ether  is  evaporated  and  the  residue 
heated  at  I20°-i3o°;  the  resulting  ketonic  ester, 
CH3COCH2OOCR,  is  separated  from  sodium  chloride 
and  treated  with  semicarbazine,  in  acetic  acid  solution 


'Cf.  Hans  Meyer,  M.  25,  476  (1904);    Wegscheider,  Ibid.  23,  383 
(1902);   A.  Werner  and  W.  Seybold,  B.  37,  3658  (1904). 
2  Carl  Graebe,  Ann.  340,  244  (1905). 


APPENDIX.  l6l 

(vide  p.  164).    The  semicarbazones  so  produced   crys- 
tallize well  and  can  be  recognized  without  difficulty.1 

• 

DETERMINATION   OF   CARBONYL. 

Cf.  p.  68. 

PREPARATION  OF  PHENYLHYDRAZONES.      Cf.  p.  69. 

Propargylic  aldehyde  fails  to  yield  a  hydrazone;  with 
hydrazine  and  phenylhydrazine  it  forms  pyrazole  and 
phenylpyrazole,  respectively.2 

PREPARATION    OF   SUBSTITUTED   HYDRAZONES.     Cf.   p.  72. 

Benzylphenylhydrazine  has  been  used  with  advantage 
for  the  separation  of  xylose  and  arabinose,  not  only  from 
other  sugars  but  also  from  each  other.  The  xylose 
derivative  is  the  more  soluble.3 

Many  sugars  contained  in  mixtures  may  be  separated 
and  isolated  in  the  'form  of  hydrazones  by  the  addition 
of  first  one  aromatic  hydrazine  and  then  a  second.  The 
two  employed  most  successfully  are  phenylhydrazine  and 
phenylmethylhydrazine,  the  former  precipitates  ^-man- 
nose  and  dextrose,  the  latter  d-galatose,  d-arabinose,  and 
rhodeose.  Galactose  and  rhamnose  may  be  separated 
by  phenylmethylhydrazine  alone,  because  the  rhamnose 
hydrazone  is  very  readily  soluble  in  dilute  alcohol.4 

d-Phenylamylhydrazine,  CH3CH(C2H5)CH2N(C6H5)- 
NH2,  has  proved  of  service  in  the  resolution  of  racemic  ke- 

1Rene  Locquin,  C.  r.  138,  1274  (1904). 

2  L.  Claisen,  B.  36,  3664  (1903). 

3R.  Hauers  and  B.  Tollens,  B.  36,  3306  (1903). 

*  Emil  Votocek  and  R.  Vondracek,  B.  37,  3854  (1904). 


1 62  APPENDIX. 

tones  and  aldehydes  into  their  optically  active  forms.1 
The  hydrazine  is  prepared  from  d-sunyl  bromide  and 
sodium  phenylhydrazine,  in  presence  of  benzene.  It  boils 
at  i73°-i75°  (50  mm.)  and  has  [a]D=+4°  45',  or  after 
6  weeks,  [a]D=+6°  4o'.2 

The  /?-naphthylhydrazones  of  arabinose  and  of  dex- 
trose are  much  less  soluble  in  alcohol  (96  per  cent)  than 
the  corresponding  compounds  of  xylose  and  laevulose, 
respectively,  consequently  ft-naphthylhydrazine  can  be 
used  with  advantage  to  separate  the  constituents  of  these 
pairs  of  sugars.3  Vide  also  p.  93. 

Certain  hydrazines  can  decompose  the  hydrazones  of 
various  sugars,  forming  a  new  hydrazone  and  liberating 
the  original  hydrazine.  The  action  is  dependent  on  the 
second  hydrazone  being  less  soluble  than  the  first  one. 
A  similar  reaction  takes  place  between  two  hydrazones 
of  different  sugars,  the  particular  combination  which  is 
least  soluble  being  precipitated.  If  S,  S\  etc.,  represents 
the  sugars  and  H,  HI,  etc.,  the  hydrazine  or  hydrazone 
radicle,  the  reactions  may  be  represented  by  the  equations 
SH  +  Hi  =  SHi  +  H,  and  SH  +  SiH^SH^SiH,  re- 
spectively. Both  reactions  are  accelerated  by  the  presence 
of  acetic  acid.4 

The  production  of  various  hydrazones  of  sugars  hi 
acetic  acid  solution  has  been  described.5 

Methylphenylhydrazine,  C6H5NCH3NH2,  reacts  readily 


1  Carl  Neuberg  and  Max  Federer,  B.  38,  868  (1905). 

2  Ibid.  38,  866  (1905). 

8  A.  Hilger  and  S.  Rothenfusser,  B.  35,  4444  (1902) 
4E.  Votocek  and  R.  Vondracek,  B.  38,  1093  (1905). 
•Rudolf  Ofner,  B.  37,  4399  (1904). 


APPENDIX.  163 

with  d-fructose,  but  not  with  dextrose,  in  aqueous  alcoholic 
solution  containing  acetic  acid.1 

INDIRECT    METHOD.       Cf.  p.  74. 

The  following  modification  of  the  phenylhydrazine 
method  for  the  determination  of  carbonyl  (vide  p.  74 
et  seq.)  has  been  proposed.2  The  evolved  nitrogen  is 
removed  from  the  apparatus  by  means  of  a  current  of 
carbon  dioxide,  the  absorption  of  this  gas  by  the  Fehling 
solution  being  prevented  by  covering  the  latter  with  a 
layer  of  molten  paraffin.  Benzene  is  removed  by  means 
of  a  mixture  of  nitric  and  sulphuric  acids  contained  in  a 
bulb-absorption,  or  other  apparatus  and  the  nitrogen  is 
measured  in  any  suitable  vessel. 

PREPARATION   OF    OXIMES.      Cf.  p.  80. 

In  addition  to  the  substances  mentioned  on  p.  84, 
additive  compounds  of  hydroxylamine  and  certain  un- 
saturated  esters  such  as  methyl  acrylate,  have  also  been 
described.3 

Ethyl  cinnamate  and  hydroxylamine,  in  aqueous- 
alcoholic  solution,  yield  phenylisoxazolone.4 

Propargylic  aldehyde,  HCiCCHO,  and  hydroxylamine, 
instead  of  forming  an  oxime,  yield  isoxazole, 


1  Carl  Neuberg,   B.   37,  4616  (1904).     Cf.   R.   Ofner,  M.   25,   1153 
(1904). 

2  Watson  Smith,  Jun.,  Ch.  N.  93,  83  (1906). 

3  B.  37,  252  (1904)- 

*A.  Tingle,  Am.  Chem.  Journ.  24,  50  (1900);   Ibid.  34,  471(1905). 


1 64  APPENDIX. 

HC:N— ^ 

|  /O,  which,  with  platinum  chloride,  forms  the 

HC  :  CH 

salt,  2C3H3ON.PtCl4.1 

jl-Phenylhydroxylamine,  C6H5NHOH,  is  a  general 
reagent  for  aldehydes,  especially  those  of  the  aromatic 

RCH. 

series.     It  forms  aldoximes  of  the  formula.        |      \O.2 

C6H5N- 

Preparation  of  Semicarbazine  Sulphate.     Cf.  p.  87. 

A  modified  method  of  preparing  semicarbazine  has  been 
worked  out.3 

Preparation  of  Semicarbazones.     Cf.  p.  87. 

Semicarbazones  are  obtained  readily  by  dissolving 
the  free  base  in  the  smallest  requisite  quantity  of  water, 
adding  a  few  drops  of  acetic  acid  and  then  the  aldehyde 
or  ketone.  Sufficient  ethyl  or  methyl  alcohol  is  poured 
in  to  give  a  clear  solution,  after  which  the  liquid  is  warmed 
on  the  water  bath  for  15  minutes. 

The  regeneration  of  an  aldehyde  or  ketone  from  its 
semicarbazone  is  effected  by  boiling  for  an  hour,  in  a 
reflux  apparatus,  with  a  slight  excess  of  sulphuric  acid 
(15  per  cent).  The  aldehyde  or  ketone  is  then  removed 
by  steam  distillation,  and  the  residual  liquid  is  concen- 
trated and  cooled.  Hydrazine  sulphate  crystallizes  and 
the  mother-liquor  contains  semicarbazine  sulphate. 

1  L.  Claisen,  B.  36,  3664  (1903). 

2  Giuseppe  Plancher  and  Galeazzo  Piccinini,  Atti.  R.  Accad.  Lincei, 
[v.]  14,  ii,  36  (19°S)' 

8  Louis  Bouveault  and  Rene  Locquin,  Bull,  [iii],  33,  162  (1905). 


APPENDIX.  165 

After  neutralization  with  potassium  carbonate,  concen- 
tration under  reduced  pressure  and  treatment  with  alcohol, 
two- thirds  of  the  hydrazine  used  initially  may  be  re- 
covered as  sulphate.1 

Certain  unsaturated  ketones,  such  as  mesityl  oxide, 
combine  with  2  mol.  of  semicarbazine,  i  mol.  adds  to 
the  double  linkage,  and  i  mol.  reacts  with  the  CO  group.2 

The  semicarbazones  of  ketones  which  do  not  contain 
a  C:C  double  linkage  are  usually  converted,  without 
difficulty,  into  highly  crystallizable  phenylsemicarbazones, 
by  boiling  for  a  short  time  with  aniline.3  This  procedure 
is  advantageous  when  the  semicarbazone  is  oily. 


HYDRAZIDE  DERIVATIVES  OF  KETONES.      Cf.  p.  93. 

Many  of  the  sugars  form  very  sparingly  soluble  com- 
pounds with  certain  acid  hydrazides,  RCONHNH2, 
from  these  derivatives  the  sugars  can  be  regenerated 
easily.  The  hydrazides  of  the  following  acids  have 
given  the  best  results:  p-Brom  and  p-chlorbenzoic,  salicylic, 
gallic,  and  ft-napkthylsulphonic.  By  means  of  the  first 
of  these  hydrazides  it  is  possible  to  detect  an  aldcse 
in  the  presence  of  large  quantities  of  ketoses  or  bioses, 
which  latter  do  not  react.  Sugars  of  the  ketose  type  are 
not  affected  by  semicarbazine.4 

1  Louis  Bouveault  and  Rene  Locquin,  Bull,  [iii],  33,  162  (1905). 

2  Hans  Rupe  and  Paul  Schlochoff,  B.  36,  4377  (1903);  H.  Rupe  and 
E.  Hinterlach,  Ibid.  40,  4764  (1907). 

3W.  Borscheand  C.  Merkwitz,  Ibid.,  37,  3177  (1904). 
4  Richard  Kahl,  Z.  Ver.  Deut.  Zucker-Ind.  1091  (1904). 


l66  APPENDIX, 


OTHER   DERIVATIVES    OF    ALDEHYDES   AND   KETONES. 

Cf.  p.  94. 

Separation  of  Aromatic  Aldehydes. — Cyclopentanone 
(adipic  ketone)  condenses  with  aromatic  aldehydes  with 
the  greatest  ease,  in  presence  of  aqueous  alcoholic  alkali 
hydroxides.  The  products  crystallize  readily  and  their 
formation  is  not  affected  by  the  presence  of  ketones  or 
aliphatic  aldehydes.  These  latter  compounds  either  fail 
to  react  with  the  pentanone,  or  yield  oily  substances, 
which  dissolve  easily  in  alcohol.  The  method  has  been 
applied  to  the  following  aldehydes:  Benzoic,  cinnamic, 
anisic,  cuminic,  and  furfur.  The  aldehydes  are  not 
easily  regenerated  from  the  condensation  product.1 

Certain  carbonyl  derivatives  containing  hydroxyl  or 
alkyloxyl  groups  are  capable  of  adding  hydrogen  bromide.2 
Aromatic  aldehydes  may  be  separated  without 
difficulty  from  hydrocarbons  and  other  impurities  by 
treatment  with  sulphurous  acid,  which  dissolves  the 
aldehyde.  The  latter  is  regenerated  by  gentle  heating 
at  1 00°,  or  by  means  of  a  current  of  air.3 

Ketones  containing  the  group,  — CH2CO  or  >CHCO 
react  readily  with  sodium,  whereas  those  with  the  group 
CRsCO  are  not  affected  by  the  metal.  In  this  manner 
fenchone  can  be  completely  freed  from  camphor.  When 
a  mixture  of  the  two  ketones  is  distilled  with  sodium  only 
the  former  passes  over.4 

1  Curt  Mentzel,  B.  36,  1499  (1903). 

2  Th.  Zincke  and  G.  Miihlhausen,  B.  38,  753  (1905). 
*  German  Patent  154,499. 

4  F.  W.  Semmler,  B.  40,  4591  (1907). 


APPENDIX.  167 

Reference  has  already  been  made  to  the  acetyl  deriva- 
tives of  certain  diketones.  Cf.  p.  143  and  to  their  re- 
action with  phenylcarbamide.  Cf.  p.  150. 


DETERMINATION  OF  CARBONYL  DERIVA- 
TIVES BY  HYDROLYSIS. 

The  following  new  method  for  the  determination  of 
aldehydes  and  ketones  provides,  simultaneously,  a  direct 
and  indirect  means  of  estimation: 

The  oxime,  phenylhydrazone,  or  osazone,  is  heated 
on  the  water-bath  for  an  hour,  with  100  cc.  of  standard 
hydrochloric  acid,  in  a  flask  having  a  long  narrow  neck. 
The  regenerated  aldehyde  or  ketone  may  be  removed  and 
weighed  as  a  control.  The  excess  of  acid  is  titrated 
with  o.o i N  sodium  hydroxide.1  The  method  is  stated  to 
give  good  results,  but  it  is  probable  that,  in  many  cases, 
it  would  be  desirable  to  determine  by  special  experiment, 
the  most  favorable  concentration  of  the  acid  and  the 
duration  of  heating. 

DETERMINATION  OF  THE  PROPENYL  GROUP, 
-CH:CHCH3,  AND  OF  THE  ALLYL  GROUP, 
-CH2CH:CH2. 

Although  the  procedure  for  distinguishing  these  groups 
has  only  been  worked  out  qualitatively,  there  is  little 
doubt  that  it  could  be  developed  into  a  quantitative 

1  Siro  Grimaldi,  Staz.  sperim.  agrar.  ital.  35,  738;  C.  1903,  i,  97; 
Journ.  Chem.  Soc.  84,  II.  342  (1903). 


168  APPENDIX. 

method.  Propenyl  compounds,  in  benzene  solution, 
when  well  shaken  with  a  saturated  aqueous  solution  of 
mercuric  acetate,  soon  deposit  crystals  of  mercurous 
acetate.  Ally!  derivatives,  on  the  other  hand,  under 
similar  conditions  yield  additive  compounds  with  mer- 
curic acetate,  which  usually  remain  in  solution.  The 
apiole  derivative  is,  however,  extremely  sparingly  soluble 
in  water.1 


DETERMINATION  OF  THE  ETHYLENE  GROUP 
>C:C<  IN  AMINES. 

The  amine  is  converted  into  the  benzenesulphonyl 
derivative  by  means  of  benzenesulphonic  chloride  in  the 
ordinary  manner,  vide  pp.  27,  107.  The  product  is 
ground  up  with  potassium  permanganate  in  aqueous 
solution.  In  the  case  of  insoluble  compounds  the  per- 
manganate (1.5  parts)  is  dissolved  in  ethyl  acetate  (1000 
parts)  to  which  a  few  drops  of  water  are  added.  The 
solution  is  stable.  Derivatives  of  unsaturated  amines 
absorb  i  atom  of  oxygen  for  each  >C:C<  group,  but 
with  ij  atoms  of  oxygen  the  solution  remains  pink.  The 
reaction  takes  place  quickly,  but  is  most  rapid  in  aqueous 
solution.  Benzenesulphonyl  derivatives  of  saturated 
amines  do  not  discharge  the  color  of  the  permanagnate 
solution.2 


1  L.  Balbiano  and  V.  Paolini,  B.  36,  3578  (1903). 

2  Alexander  Ginzberg,  B.  36,  2707  (1903). 


APPENDIX.  169 

DETERMINATION  OF  THE  ALIPHATIC  AMINO 
GROUP.    Cf.  p.  95. 

TITRATION  WITH   IODINE. 

The  following  method  has  been  worked  out  for  benzi- 
dine  and  tolidine.  With  suitable  modifications  it  could 
doubtless  be  applied  to  other  amines: 

The  base  (about  5  grams)  is  dissolved  in  hot  water 
containing  hydrochloric  acid  (5  cc.),  and  when  cold  the 
solution  is  diluted  to  500  cc.  Of  this  liquid  25  cc.  are 
neutralized  with  solution  of  sodium  hydrogen  carbonate 
until  a  slight  precipitate  forms,  this  is  then  redissolved 
by  the  addition  of  a  drop  of  highly  dilute  hydrochloric 
acid.  The  liquid  is  diluted  to  500  cc.  and  0.05 N  iodine 
solution  is  added  slowly,  while  stirring,  until  no  further 
precipitate  is  produced  and  a  drop  of  the  supernatant 
liquid  gives  a  blue  color  with  starch-paper;  254  parts 
of  iodine=i84  parts  of  benzidine  =  2ii.6  parts  of  toli- 
dine.1 

Amines,  imines,  nitrile  bases,  amides,  and  amino  acids 
all  react  with  calcium  hypochlorite  solution,  the  quantity 
of  active  chlorine  in  the  liquid  being  decreased  in  pro- 
portion to  the  amount  of  nitrogenous  material  added. 
At  the  ordinary  temperature  the  ammonium  bases  do 
not  behave  in  this  manner.  The  quantity  of  chlorine 
which  enters  into  reaction  differs  for  different  substances 
and  requires  to  be  determined  specially  in  each  case. 
Alkaline  hypochlorite  solution  may  be  exposed  to  light 

1  Armand  Roesler  and  Boris  Glasmann,  Ch.  Ztg.  27,  986  (1903). 


170  APPENDIX. 

for  about  30  hours  without  undergoing  change,  provided 
that  air  is  excluded.  The  analysis  is  carried  out  in  the 
following  manner:  In  a  flask  of  50  cc.  capacity  there  are 
placed  calcium  hypochlorite  solution  containing  1.5  to 
2.0  per  cent  of  active  chlorine  (2.0  cc.),  iN  soldium  hy- 
droxide solution  (20  cc.) ,  and  i  to  5  cc.  of  one  per  cent  solu- 
tion of  the  substance  under  examination.  The  flask  is 
filled  completely  with  water,  closed,  and  allowed  to  remain 
12-15  hours  in  the  dark.  Solution  of  arsenious  acid  is 
now  added  in  quantity  equivalent  to  the  amount  of  calcium 
hypochlorite  originally  taken,  then  normal  sulphuric 
acid  (20  cc.)  and  concentrated  solution  of  sodium  hydrogen 
carbonate  (10  cc.).  The  excess  of  arsenite  is  finally 
determined  by  titration  with  iodine.1 

Some  of  the  ammo  acids  may  be  TITRATED  by  aqueous 
potassium  hydroxide  in  presence  of  litmus  or  phenol- 
phthalein,  provided  that  formaldehyde  solution  is  first 
added  to  the  amino  derivative.  The  aldehyde,  combines 
with  the  NH2  group  and  so  destroys  its  basic  properties, 
leaving  the  carboxyl  free  to  react  with  the  alkali.2  Cf. 

P-Si- 

For  the  isolation  of  AMINO  ACIDS  ^-nitrotoluene-2-sul- 

phonic  chloride?  and  ft -anthraquinonesul phonic  chloride4 
have  been  recommended.  The  following  method  gives 
excellent  results,  the  products  crystallize  readily,  and  the 
yields  of  condensation  compounds  are  quantitative. 
It  is  applicable  to  the  examination  of  urine  and  to  the 


1  J.  Effront,  B.  37,  4290  (1904). 

2  Hugo  Schiff,  A.  319,  59,  287  (1901);  325,  348  (1902). 

3  M.  Siegfried,  Z.  physio).  Ch.  43,  69  (1904). 

4  O.  Hinsberg,    B.  33,  3526  (1900). 


APPENDIX.  171 

determination  of  a-  and  /3-amino  acids,  amino  aldehydes, 
hydroxy  amino  acids,  diamino  acids,  and  also  to  peptides 
(polypeptides) .  The  amino  derivative  is-  mixed  with 
alkali  hydroxide  in  aqueous  solution  and  the  necessary 
quantity  of  a-naphthylisocyanate,  CioH7N.CO,  is  added 
in  one  portion.  The  mixture  is  well  shaken  for  2-3 
minutes,  at  intervals,  during  £  to  J  of  an  hour,  the  stopper 
being  raised  after  each  shaking  to  permit  of  the  escape 
of  carbon  dioxide.  When  the  reaction  is  completed  the 
liquid  is  filtered  from  a-dinaphthylcarbamide  and  the 
naphthylhydrantoic  acid,  Ci0H7NHCONHRCO2H,  is 
precipitated  by  acidification. 

a-Naphthyl  isocyanate  is  prepared  by  the  distillation 
of  a-naphthylurethane  with  a  considerable  excess  of 
phosphoric  anhydride.  It  is  a  liquid  which  boils  at  270° 
and  does  not  evolve  obnoxious  vapor.  Apparently  it  has 
not  been  applied  to  the  determination  of  hydroxyl,  although 
it  should  be  capable  of  rendering  good  service.1  Cf. 
PP.  35>  J5o. 

AMINO  ACIDS,  PEPTONES,  ALBUMOSES,  and  ALBUMINOID 

COMPOUNDS  may  often  be  separated  by  means  of  their 
carbamic  acids,  these,  with  the  metals  of  the  alkali  earths, 
form  salts  of  varying  solubility  and  from  the  salts  the 
original  amino  derivative  may  be  regenerated  without 
difficulty.  The  method  of  procedure  is  illustrated  by 
the  following  example:  Aminoacetic  acid  (3.8  grams)  is 
dissolved  in  a  little  water  containing  hydrochloric  acid 
(25  per  cent,  10  cc.),  the  acid  is  neutralized  with  baryta 
water  and  then  more  baryta  solution  (o.iN,  357  cc.) 
is  added.  When  cold  the  liquid  is  treated  with  carbon 

1  C.  Neuberg  and  A.  Manasse,  B.  38,  2359  (1905). 


172  APPENDIX. 

dioxide  until  it  is  no  longer  alkaline,  phenolphthalein 
being  used  as  indicator.  The  mixture  is  now  made  slightly 
alkaline  with  baryta  water.  After  remaining  for  an  hour 
at  4°  the  precipitate  is  filtered  off  and  washed  with  ice- 
cold  water  containing  barium  hydroxide,  until  it  is  free 
from  chloride.  This  treatment  gives  the  pure  barium 
carbamate;  in  order  to  regenerate  the  original  amino 
acid  the  salt  is  heated  on  the  water-bath  with  water 
and  ammonium  carbonate,  the  filtrate,  on  evaporation, 
deposits  aminoacetic  acid  in  a  high  state  of  purity. 
Yield  3.15  grams.1 

ANALYSIS  OF  SALTS  AND  DOUBLE  SALTS,    Vide  p.  173. 

ACYLATION    OF   ALIPHATIC   AMINES.       Vide  p.   174. 

ALKYLATION  OF  ALIPHATIC  AMINES.    Vide  pp.  149, 177. 

DETERMINATION   OF   AROMATIC   AMINO 
GROUPS.     Cf.  p.  97. 

CONVERSION  OF  THE  BASE  INTO  AN  Azo  DYE.     Cf.  p.  99. 

The  following  method  has  been  worked  out  for  the 
determination  of  ^-nitrobenzenediazonium  chloride :  Sub- 
limed /3-naphthol  (1.44  grams)  is  mixed  in  a  3  lit.  vessel  with 
aqueous  sodium  hydroxide  (30-35  per  cent,  2  cc.)  and 
warm  water  (10-20  cc.).  As  soon  as  solution  is  com- 
plete the  liquid  is  diluted  to  2-2.5  ^.  w^tn  water  at 
25°~3°°>  acidified  with  acetic  acid  and  crystallized  sodium 
acetate  (about  50  grams)  is  added.  The  diazonium 

4M.  Siegfried,  B.  39,  397  (1906). 


APPENDIX.  173 

solution  is  run  in  from  a  burette,  the  mixture  being  con- 
stantly stirred.  Towards  the  end  of  the  reaction  a  drop 
of  the  liquid  is  placed  on  filter-paper  and  the  colorless 
rim  around  the  precipitate  is  tested  with  a  drop  of  dia- 
zonium  solution,  when  this  procedure  gives  an  indefinite 
color  or  none  at  all,  a  small  portion  (3-4  cc.)  of  the 
liquid  is  filtered  and  divided  into  two  parts,  to  one  a 
drop  of  /3-naphthol  solution  is  added,  to  another  a  drop 
of  the  diazotized  liquid;  several  such  tests  are  made  and 
as  soon  as  the  filtrate  becomes  rose  colored  with  a  drop 
of  the  /?-naphthol  solution  the  titration  is  at  an  end. 
The  mean  of  the  last  two  readings  of  the  burette  is  taken 
as  giving  the  correct  quantity  of  diazonium  chloride. 
The  accuracy  of  the  method  is  stated  to  be  0.05  per 
cent.1 


ANALYSIS  OF  SALTS  AND  DOUBLE  SALTS.      Cf.  pp.  97,  105. 

Pyridone  and  lutidone  form  abnormal  salts  such  as 
(C7H9ON)2.HC1  with  the  haloid  acids.2  Vide  p.  106. 

The  alkaloid  yohimbine  eliminates  i  molecule  of  water 
when  it  combines  with  acids  to  form  salts.3 

A  number  of  salts  of  pyrone,  C5H4O2,  have  been  de- 
scribed and  their  constitution  discussed.4 

The  chlorplatinate  of  2-oxy-6-anilmopyrimidine  (phen- 


1  Carl  Schwalbe,  B.  38,  3072  (1905). 

2  P.  Petrenko-Kritschenko  and   F.  Stamoglu,   J.  Russ.  Phys.  Chem. 

Soc.  34,  7°6  (iQ02)- 

3Pictet,     "The    Vegetable    Alkaloids,"     p.     492.      Translated   by 
Biddle. 

4  Richard  Willstatter  and  Rudolf  Pummerer,  B.  37,  3740  (1904). 


174  APPENDIX. 

ylcytosine)    crystallizes  with  iH2O  l  and  scatosine  yields 
the  hydrochloride,  C10H16O2N2.3HCL2 

Abnormal  salts  are  formed  by  trialkyltrimethylenetri- 
amines,3  and  a  list  of  those  prepared  from  other  com- 
pounds has  been  published.4  Cf.  p.  164. 


ACYLATION.      Cf.  pp.  106,  143,  148. 

A  simple  method  of  preparing  acetyl  derivatives  in 
aqueous  solution  consists  in  dissolving  acetic  anhydride 
(12.3  grams)  in  water  (120  cc.),  adding  the  aromatic 
amino  or  imino  derivative  alone,  or  dissolved  in  dilute 
acetic  acid  and  shaking  the  mixture  thoroughly.  If 
the  amines  are  employed  in  the  form  of  hydrochlorides 
the  equivalent  quantity  of  sodium  acetate  must  also  be 
added.  The  method  is  of  varied  application:  by  its  use 
^-hydroxyphenylglycine,  HOCel^NHCHsCC^H,  yields 
an  acetyl  derivative  without  difficulty,  although  it  is  not 
affected  by  boiling  with  acetic  anhydride.5 

Feebly  basic  compounds  may  often  be  benzoylated  by 
heating  them  with  an  equal  part  of  benzoic  acid  and  about 
o.i  part  of  anhydrous  sodium  benzoate,  benzene  (i  part) 
is  usually  used  as  the  solvent.6 


1  Henry  L.  Wheeler  and  H.  Stanley  Bristol,  Am.  Chem.  Journ.  33, 

459  (i9°5)- 

2  Swain,  Beitrag  chem.  Physiol.  Pathol.  3,  445  (1903). 

3  Alfred  Einhorn  and  August  Prettner,  Ann.  334,  210  (1904). 

4  Werner,  B.  36,  147  (1903).     Cf.  Morgan  and  Micklethwait,  Journ. 
Chem.  Soc.  89,  863  (1906);    Pickard  and  Kenzon,  Ibid.  89,  268  (1906). 

5  Auguste   Lumiere,   Louis   Lumiere  and   Henri    Barbier,    Bull,   [iii] 

33,  783  (1905). 
•  Gustav  Heller,  B.  37,  3113  (1904). 


APPENDIX.  175 

Quinoline  is  converted  by  sodium  hydroxide  and 
benzoyl  chloride  into  o-benzoylaminocinnamic  aldehyde,1 
and  corresponding  compounds  are  formed,  by  the  action 
of  alkali  hydroxides  on  the  alkyl  haloid  additive  products 

CH:CH— 
of    quinoline,    such    as    C6H4^  ,/CH.2      Iso- 

xNCl(CH3r 

quinoline  does  not  react  with  sodium  hydroxide  and 
benzoyl  chloride,  but  if  the  alkali  is  replaced  by  potassium 
cyanide,  the  base  adds  a  nitrile  and  a  benzoyl  group.1 
Benzthiazole,  with  alkali  and  benzoyl  chloride,  is  con- 
verted into  a  mixture  of  dibenzoyl-0-aminothiophenol, 
CeHsCONHCeH^SCOCel^,  and  phenylbenzthiozole, 

C6H4/ 


ACETYLHYDROXAMIC      CHLORIDE,      CH3CC1:NOH,      IS 

admirably  adapted  for  the  characterization  of  amines, 
because  the  acetamide  oximes,  CH3C(:NOH)NHR, 
which  it  forms  with  them,  are  prepared  without  difficulty 
and  crystallize  well.  The  reaction  often  takes  place  at 
the  ordinary  temperature,  in  ether  solution,  the  amide 
oxime  being  liberated  by  means  of  sodium  hydroxide 
from  the  hydrochloride  which  is  first  formed.  Acetyl- 
hydroxamic  chloride  is  prepared  by  dissolving  hydroxyl- 
amine  hydrochloride  (325  grams),  in  water  (300  cc.),  and 
adding  sodium  hydroxide  (255  grams),  dissolved  in  water 
(600  cc.).  The  mixture  is  cooled  and  gradually  poured 
into  aldehyde  (200  grams)  and  water  (100  grams)  con- 


1  Arnold  Reissert,  B.  38,  3415  (1905). 
*  Roser,  Ann.  272,  222  (1893). 


176  APPENDIX. 

tained  in  a  flask,  surrounded  by  a  freezing  mixture. 
After  15  hours  the  liquid  is  saturated  with  sodium  chloride 
and  extracted  eight  times  with  ether  (1.5  lit.).  After 
drying  with  calcium  chloride  the  ether  is  fractionated 
by  means  of  a  bulb  apparatus.  The  yield  of  oxime,  b.  p. 
ii2°-ii4°,  is  80  per  cent  of  the  theoretical.  Its  con- 
version into  the  chloride  is  effected  by  dissolving  10  grams 
of  it  in  5  per  cent  aqueous  hydrochloric  acid  (40  cc.), 
cooling  the  liquid  in  a  freezing  mixture  and  passing  in 
chlorine  until  12  grams  of  the  gas  have  been  dissolved. 
The  liquid  is  allowed  to  remain  in  the  freezing  mixture 
for  some  time  and  is  then  extracted  twice  with  ether, 
the  aqueous  portion  is  saturated  with  ammonium  sulphate 
and  extracted  eight  times  more  with  ether.  The  com- 
bined ethereal  solutions  are  washed  twice  with  a  little 
water,  dried  with  calcium  chloride  and  the  ether  dis- 
tilled under  reduced  pressure,  at  a  temperature  not 
exceeding  25°.  The  residual  chloride  solidifies  in  a 
freezing  mixture.  It  decomposes  rather  readily,  but 
when  dissolved  in  ether  or  alcohol,  the  liquid  can  be 
retained  for  some  days.  Apart  from  this  drawback, 
the  hydroxamic  chloride  is  superior  to  acetyl  chloride 
because  of  its  stability  with  water  or  alcohol.  Yield 
88  per  cent  of  the  theoretical.  With  phenols  it  forms 
acetyl  oximes,  ROC(:NOH)CH3,  under  conditions  simi- 
lar to  those  described  above  for  amines.1 

1  Heinrich  Wieland,  B.  40,  1676  (1907). 


APPENDIX.  177 


ALKYLATION  OF  AMINES.      Cf.  pp  108,  149. 

A  number  of  amines,  especially  tertiary  bases,  which 
do  not  react  with  alkyl  halides,  may  be  alkylated  by 
means  of  dimethyl  or  diethyl  sulphate.1 

The  influence  of  various  so-called  ' '  indifferent  "  solvents 
on  the  reaction  between  amines  and  alkyl  halides  has 
been  studied  extensively.2 

a-Naphthylamine  s-trinitrobenzene  does  not  combine 
with  ethyl  iodide  in  presence  of  magnesia  or  silver  oxide.3 

Caffeine  alkyl  iodides  are  oxidized  by  certain  specimens 
of  ether.  The  action  takes  place  with  pure  ether  which 
has  been  in  contact  with  air  for  some  months.4 


SEPARATION   OF  PRIMARY  AND  SECONDARY 
AMINES  BY  ACYLATING  AGENTS. 

Primary  and  secondary  amines  may  be  separated 
quantitatively  by  one  of  the  following  methods:  The 
first  process  is  applicable  to  compounds,  the  radicles 
of  which  contain  less  than  seven  carbon  atoms.  Sub- 
stances having  groups  of  higher  molecular  weight  are 
separated  by  the  help  of  the  second  method.  (I)  The 
mixture  of  bases  is  treated  with  4  molecular  proportions 

1H.  Decker,  B.  38,  1144  (1905). 

2  N.  Menschutkin,   Z.    17,  194    1895);   34,    157  (1900);  B.   30,  2775 
(1897). 

3  Harold   Hibbert  and   John  J.   Sudborough,  Journ.  Chem.  Soc.  83, 
1341  (1903). 

4  A.  I.  Rossolimo,  B.  38,  774  (1905). 


178  APPENDIX. 

of  aqueous  potassium  hydroxide  (12  per  cent)  and  benzene- 
sulphonic  chloride  (1.5  mol.)  is  added  gradually,  the  mix- 
ture being  well  shaken  and  finally  warmed  to  decompose 
the  last  traces  of  the  chloride.  If  the  bases  are  used  in 
aqueous  solution  the  alkali  should  be  proportionately 
more  concentrated.  In  the  case  of  compounds  which 
are  readily  volatile,  the  mixture  of  alkali  and  chloride 
should  be  added  to  the  amine  and  the  liquid  cooled  with 
ice.  Hydrochloric  acid  in  excess  is  now  run  in,  and  the 
precipitate  filtered  out  or  extracted  with  ether.  The  solid 
or  the  residue  obtained  after  the  ether  has  been  distilled 
is  then  heated  on  the  water-bath,  in  a  reflux  apparatus, 
for  15  minutes  with  sodium  ethylate  (about  0.8  gram  of 
sodium  in  20  cc.  of  96  per  cent  alcohol).  The  alkaline 
liquid  is  diluted  with  water,  the  alcohol  volatilized  and 
the  benzenesulphamides  of  the  secondary  bases  removed 
by  filtration.  When  acidified  the  filtrate  deposits  the 
benzenesulphamides  of  the  primary  amines.  The  original 
compounds  may  be  regenerated  from  the  amides,  if 
desired,  by  heating  with  sulphuric  or  hydrochloric  acid 
at  i2O°-i5o°.  (II)  The  procedure  in  the  case  of  sub- 
stances of  higher  molecular  weight  is  exactly  as  described 
above,  except  that  after  the  alcohol  has  been  volatilized 
the  liquid  is  acidified  with  hydrochloric  acid  and  the 
precipitate  removed  and  dried.  It  is  now  dissolved  in 
anhydrous  ether  and  the  solution  warmed  gently  on  the 
water-bath,  in  a  reflux  apparatus,  during  6-8  hours, 
pieces  of  sodium  being  added  from  time  to  time.  After 
this  the  liquid  is  cooled,  the  solid  washed  with  ether  and 
collected  on  a  filter.  When  treated  with  hydrochloric 
acid  it  gives  the  benzenesulphonic  derivatives  of  the 


APPENDIX.  179 

primary  bases,  whereas  those  of  the  secondary  amines 
are  obtained  directly  by  evaporating  the  ethereal  filtrate 
and  washings.1 


DETERMINATION  OF  THE  AMIDO  GROUP, 
— CONH2.  Cf.  p.  no. 

As  a  rule,  primary  or.  secondary  amides  with  the  group 
— CONH2  and  — CONHCO— ,  respectively,  cannot  be 
acylated  by  the  action  of  acid  chlorides  or  anhydrides, 
but  the  sodium  derivatives  of  the  amides  react  readily, 
especially  with  acid  anhydrides;  some  tertiary  amide  is 
always  formed  simultaneously.  The  method  is  not, 
however,  applicable  to  the  synthesis  of  aliphatic-aromatic 
secondary  amides:  thus  sodium  benzamide  and  acetic 
anhydride,  or  sodium  acetamide  and  benzoic  anhydride, 
yield,  chiefly,  sodium  dibenzamide,  (C6H5CO)2NNa,  no 
acetbenzamide,  CHsOONHCOCeHs,  being  produced.2 

Primary  and  even  secondary  amides  may  be  benzoy- 
lated  by  means  of  benzoyl  chloride  and  pyridine.  The 
method  fails  with  acetamide  and  does  not  give  good  results 
when  used  for  acetylation.  Other  processes  have  also 
been  investigated.3 


1O.  Hinsberg  and  J.  Kessler,  B.  38,  906  (1905). 

2  Arthur  Walsh  Titherley,  Proc.  Chem.  Soc.  (London),  20,  187  (1904). 

•Arthur  Walsh  Titherley,  Journ.  Chem.  Soc.  85,  1679  (1904). 


l8o  APPENDIX. 

DETERMINATION  OF  THE  IMINO  GROUP, 
>NH.    Cf.  p.  112. 

The  remarks  on  the  SALTS  of  amines  (Cf.  p.  173)  apply 
also  to  those  of  the  imino  compounds. 

The  ALKYLATION  of  imino  derivatives  is  accomplished 
by  the  same  general  methods  as  are  used  in  the  case  of 
amines.  Cf.  pp.  149,  177. 

The  ACETYLATION  of  imines  is  sometimes  complicated 
by  other  reactions.  Isatin  and  benzoyl  chloride,  at 
170°,  yield  benzoylpseudoisatin ;  indigo  when  boiled 
with  the  chloride  and  pyridine  is  converted  into  tetra- 
benzoylindigo  white.1  Compounds  containing  the  groups, 
• — CONHCO — ,  usually  fail  to  yield  acetyl  derivatives,  but 
if  any  are  formed  they  are  very  unstable.2 

DETERMINATION  OF  METHYLIMINE,   >NCH3 
Cf.  p.  114. 

Some  compounds  containing  alkyl  linked  to  nitrogen 
eliminate  alkyl  iodide  at  a  low  temperature,  and  occa- 
sionally this  occurs  when  the  substance  is  heated  alone. 
Confusion  is  thus  caused  in  attempting  to  distinguish 
between  O-alkyl  and  JV-alkyl.  The  difficulty  can  be 
overcome  by  placing  the  substance  in  a  U-tube  which  is 
heated  in  a  bath  of  sulphuric  acid  or  glycerol.  A  current 
of  carbon  dioxide  is  passed  through  the  tube  and  the 
alkyl  halide  is  absorbed  in  the  usual  manner.  The 


1  Gustav  Heller,  B.  36,  2762  (1903). 
8  Heinrich  Biltz,  Ibid.  40,  4800  (1907). 


APPENDIX.  l8l 

residual  tertiary  base  may  be  weighed  as  a  check.  The 
method  has  been  applied  to  8-nitroquinoline  methiodide, 
"  iodine  green,"  and  phenylacridinium  ethiodide.1 


DETERMINATION    OF    THE    NITRO    GROUP, 
— NO2.    Cf.  p.  129. 

The  following  process  is  applicable  to  the  determination 
of  ^-nitrotoluene : 2  The  crude  nitrotoluene  (10  cc.)  is 
mixed  with  water  (20  cc.),  iron  filings  (20  grams)  and 
hydrochloric  acid,  sp.  gr.  =  i.i9  (i  gram)  and  heated 
during  6  hours  in  a  reflux  apparatus.  The  product 
(1.2-0.3  gram)  is  dissolved  in  ether  (80  cc.)  and  the 
^-toluidine  precipitated  with  5  per  cent  ethereal  solution 
of  oxalic  acid  (25  cc.).  The  precipitate  is  washed  with 
ether  until  free  from  soluble  matter,  and  then  the  filter- 
paper  with  its  contents  is  treated  with  warm  water  and 
the  solution  titrated  with  o.iN  sodium  hydroxide  solution; 
i  cc.  o.iN  NaOH  =  0.00535  gram  ^-tolnidine= 0.00685 
gram  ^-nitrotoluene. 

A  novel  method3  of  determining  the  composition  of 
binary  mixtures  of  the  three  isomeric  nitranilines,  by 
means  of  their  melting-points,  is  described  on  page  191. 

The  use  of  titanous  chloride  is  referred  to  in  connection 
with  the  azo  group,  page  183. 


1  Hermann  Decker,  B.  36,  2896  (1903). 

2  B.  Glasmann,  B.  36,  4260  (1903). 

•  J.  Bishop  Tingle  and  H.  F.  Rolker,  Journ.  Amer.  Chem.  Soc.  3<V 

May,  1908. 


182 


APPENDIX. 


DETERMINATION  OF  THE  NITROSO  GROUP, 
—NO.     Cf.  p.  132. 

The  method  described  on  page  132  has  been  found  to 
be  quite  generally  applicable  to  compounds  of  the  type, 


ONC\         ,   but  it  fails   altogether  with  nitrosamines, 
CR2 


,    or    with    isonitroso    compounds    (oximes), 


HON:C<      ,  unless  they  react  in 

R2 

a  tautomeric  form.1  Alkyl  nitrites 
require  special  treatment  as  follows  : 
The  ester  0.1-0.3  gram  is  dissolved 
in  glacial  acetic  acid  in  the  flask, 


FIG.  21.  FIG.  22. 

acetic  acid  solution  of  aniline  (3  grams)  is  added,  and 
then  concentrated  hydrochloric  acid  (10-12  cc.).     After 


1  R.  Clauser  and  G.  Schweitzer,  B.  35,  4280  (1902). 


APPENDIX.  183 

heating  the  mixture  on  the  water-bath  for  4  hours,  or 
until  there  is  no  odor  of  nitrite,  the  excess  of  hydro- 
chloric acid  is  neutralized  with  crystallized  sodium 
acetate  and  the  product  treated  in  the  usual  manner. 
This  method  is  not  applicable  to  highly  volatile  nitrites, 
such  as  the  ethyl  derivative.  The  apparatus,  Fig.  21, 
is  far  more  convenient  than  the  older  form,  Fig.  17,  p.  133. 
The  gas  produced  during  the  reaction  is  collected  in  a 
vessel  having  two  parallel  borings  in  the  stop-cock, 
Fig.  22. 

The  use  of  titanous  chloride  is  described  in  connec- 
tion with  the  azo  groups.     Cf.  p.  183. 


DETERMINATION     OF      THE     AZO      GROUP, 
RN:NR. 

Many  azo  derivatives  may  be  determined  by  titration 
with  titanous  chloride,  TiCls.  The  commercial  chloride 
is  boiled  briskly  with  an  equal  volume  of  concentrated 
hydrochloric  acid  to  remove  traces  of  hydrogen  sulphide, 
and  then  diluted  to  twenty  times  its  original  volume 
with  water  free  from  oxygen.  In  the  absence  of  air  its 
titre  remains  unchanged  during  long  periods.  The  azo 
derivative,  dissolved  in  a  considerable  excess  of  hydro- 
chloric acid,  is  boiled  and  the  chloride  solution  added 
gradually,  the  experiment  being  carried  out  in  an  atmos- 
phere of  carbon  dioxide.  The  change  in  the  color  of 
the  azo  compound  renders  an  indicator  unnecessary. 
If  the  azo  derivative  is  sparingly  soluble  in  hydrochloric 
acid  the  reduction  proceeds  very  slowly,  in  this  case  it 
is  best  to  add  excess  of  the  chloride  and  titrate  back  with 


184  APPENDIX. 

iron  alum,  the  end-point  being  determined  by  with- 
drawing a  drop  and  testing  it  'with  potassium  thiocy- 
anate.  Insoluble  dyes  may  be  rendered  soluble  by 
sulphonation  or  decomposition.  The  concentration  of 
the  chloride  is  determined  by  titration  with  iron  alum; 
TiCl3  =  FeCl3;  4TiCl3=iRN2R. 

The  method  has  been  applied  successfully  to  the 
determination  of  the  nitro  and  nitroso  groups  in  a  number 
of  compounds.  It  offers  several  advantages  over  the 
use  of  stannous  chloride  for  this  purpose.  The  titanous 
chloride  is  added  in  excess  and  then  titrated  back  with 
a  ferric  salt,  as  described  above.  The  nitro  compounds 
are  reduced  to  amines;  6TiCl3=iNO2j  4TiCl3=iNO.1 


THE  IODINE  NUMBER.     Cf.  p.  136. 

A  comparison  2  of  the  relative  efficiency  of  the  various 
methods  which  have  been  suggested  for  the  determina- 
tion of  the  "  iodine  number  "  shows  that  it  is  preferable 
to  use  a  solution  of  iodine  monobromide  in  glacial  acetic 
acid  (Hanus),  rather  than  iodine  monochloride  (Wijs). 
The  best  results  3  are  obtained  by  adding  60-70  per  cent 
of  the  bromide  in  excess  of  the  quantity  which  actually 
enters  into  combination.  Iodine  monochloride,4  in  the 
same  solvents,  gives  slightly  higher  values,  but  only 
30  per  cent  excess  is  required.  Both  reagents  are  superior 


1  Edmund  Knecht,  B.  36,  1549  (1903). 

3  L.  M.  Tolman  and  L.  S.  Munson,  J.  Am.  25,  244  (1903). 

8  Jos.  Hanus,  Z.  Nahr.-Genussm.  4,  913  (1901). 

«J.  J.  A.  Wijs,  Ibid.  5,  497(1902). 


APPENDIX.  185 

to    the    iodine-mercuric   chloride   reagent   (Hiibl).     The 
reaction  is  complete  after  30  minutes  contact.1 


MISCELLANEOUS  METHODS. 

Under  this  heading  is  included  a  number  of  processes 
for  the  determination  of  single  substances,  such  as  methyl 
alcohol,  or  of  certain  groups  of  compounds,  such  as 
pentosans.  The  methods  have  been  selected  on  account 
of  their  utility  or  scientific  interest,  or  because  they  appear 
to  be  capable  of  development  and  generalization.  The 
list  of  topics  has  necessarily  been  very  greatly  restricted. 
The  subject  is  treated  exhaustively  in  Allen's  "Commer- 
cial Organic  Analysis." :  Fairly  full  descriptions  of  the 
newer  methods  will  be  found  in  the  "  abstracts "  of 
the  "Journal  of  the  Chemical  Society"  (London),3 
and  particularly  in  "  Chemical  Abstracts."  4 


1  Lucius  M.  Tolman,  J.  Am.  26,  826  (1904). 

2  Philadelphia,  Pa.:  P.   Blakiston's  Son   &  Co.;  London:  J.    &  A. 
Churchill,  Vol.  I  (1898),  $4.50;    Vol.  II,  pt.  I  (1899),  $3.50;    pt.  II 
(1900),  $3.50;  pt.  Ill  (1907),  $5.00;  Vol.  Ill,  pt.  I  (1900),  pt.  II  (1892), 
pt.  Ill  (1896),  Vol.  IV  (1898),  $4.50  each. 

3  Gurney  and  Jackson,  10  Paternoster  Row,  London,  E.  C.  (England), 
Price  £2  ($10.00)  per  annum. 

4  American  Chemical  Society,  Secy.  Prof.  C.  L.  Parsons,  New  Hamp- 
shire College,  Durham,  N.   H.,  U.   S.   A.     The  journal  is  published 
semi-monthly,  price  $6.00  (£1-4-0)  per  annum. 


1 86  APPENDIX. 


DETERMINATION    OF    METHYL    ALCOHOL. 

Methyl  alcohol  may  be  determined  in  presence  of 
FORMALDEHYDE  by  the  following  process : 1  Water 
(25  cc.)  is  boiled  in  a  distilling-flask  and  sodium  sul- 
phanilate  (90  grams)  is  added,  the  boiling  being  con- 
tinued until  solution  is  complete.  The  liquid  is  now 
cooled  rapidly  and  stirred  and  the  substance  under 
examination  (20  cc.)  is  added.  After  3-4  hours  at  the 
ordinary  temperature,  or  1.5-2  hours  at  35°-4o°,  the 
aldehyde  has  combined;  the  mixture  is  then  distilled, 
the  first  35  cc.  of  distillate  contain  all  the  methyl  alcohol. 
The  distillate  is  made  up  to  50  cc.  and  its  content  of 
methyl  alcohol  determined  from  its  density  at  15°.  A 
table  of  densities  is  given  in  the  original  paper.  The 
process  is  applicable  to  highly  concentrated  solutions  of 
aldehyde,  provided  the  quantity  of  sulphanilate  is  in- 
creased to  no  grams. 

Another  method  2  consists  in  diluting  the  formaldehyde 
solution  with  water  (20  vols.),  adding  excess  of  aqueous 
ammonia  and  distilling  until  half  the  liquid  has  passed 
over.  The  distillate  is  made  feebly  acid  with  acetic 
acid  and  a  convenient  portion  analyzed  by  Zeisel's 
method.  (Vide  pp.  38,  154).  Ziesel's  method  is  also 
used  for  the  determination  of  methyl  alcohol  in  crude 
wood  spirit.3  The  necessary  corrections  are  described 
in  the  original  paper. 

1  Robert  Gnehm  and  Felix  Kaufier,  Z.  ang.  Ch.  17,  673  (1904);    18, 

93  (i9°S)« 

3  Milan  J.  Stritar,  Z.  anal.  Ch.  43,  401  (1904). 

3  Milan  J.  Stritar  and  H.  Zeidler,  Ibid.  43,  387  (1904). 


APPENDIX.  187 

The  process  described  below  for  the  estimation  of 
methyl  alcohol  in  presence  of  ethyl  alcohol  has  proved 
to  be  of  great  service,  especially  in  the  analysis  of  methy- 
lated spirit  or  denatured  alcohol.  The  substance  under 
examination  is  freed  by  distillation  from  dissolved  matter 
and  the  density  of  the  distillate  determined  so  as  to 
ascertain  its  approximate  alcoholic  content.  The  den- 
sities of  ethyl  and  methyl  alcohols  are  nearly  the  same, 
consequently  only  a  single  table  of  densities  is  re- 
quired. 

To  the  distillate  water  is  added  in  such  proportion  that 
50  cc.  of  the  mixture  shall  contain  not  more  than  i  gram 
of  methyl  alcohol,  or  not  more  than  4  grams  of  the  mixed 
alcohols.  This  mixture  (50  cc.)  is  placed  in  a  flask, 
and  potassium  dichromate  (20  grams),  together  with 
dilute  sulphuric  acid  (i :  4,  80  cc.)  are  added.  After  re- 
maining during  1 8 'hours  at  the  ordinary  temperature,  the 
liquid  is  mixed  with  more  potassium  dichromate  (10  grams) 
and  sulphuric  acid  (1:1,  50  c.c),  and  boiled  during  10 
minutes,  the  last  traces  of  carbon  dioxide  being  removed 
from  the  flask  by  means  of  a  current  of  purified  air. 
The  whole  of  the  carbon  dioxide  is  absorbed  by  weighed 
tubes  containing  soda-lime.  Under  these  conditions 
the  oxidation  of  the  methyl  alcohol  to  carbon  dioxide 
and  water  is  complete,  but  a  subtractive  correction  must 
be  applied  of  o.oi  gram  of  carbon  dioxide  for  each  gram 
of  ethyl  alcohol  which  was  present  originally. 

Under  the  conditions  described  above  ethyl  alcohol 
is  converted  into  acetic  acid.1 


1  Thomas  Edward  Thorpe  and  John  Holmes,  Journ.  Chem.  Soc.  85, 
i  (1904). 


1 88  APPENDIX. 

Ethyl  alcohol  in  the  presence  of  methyl  alcohol  may 
be  determined  by  a  somewhat  similar  process.1 

DETERMINATION  OF  ETHYL  ALCOHOL. 

Vide  p.  187. 

DETERMINATION  OF  PHENOL. 

An  improved  method  for  the  titration  of  phenol  by 
means  of  bromine  has  been  worked  out.2 

DETERMINATION  OF  FORMALDEHYDE.      Cf.  p.  1 86. 

The  intrinsic  importance  of  this  compound  and  its 
wide  use  in  the  Arts  justifies  the  separate  treatment 
of  the  procedure  for  its  determination.  It  has 
been  found  that  the  volumetric  "  aniline,"  and  also 
the  gravimetric  "  heraxmethylenetetramine "  methods 
are  untrustworthy.3  Romijn's  "  iodometric "  and 
"  cyanide "  processes,4  are  recommended,  especially 
for  dilute  solutions.  The  liquid  containing  about 
0.015  gram  of  formaldehyde,  is  mixed  with  25  cc. 
of  o.iN  iodine  solution  and  enough  concentrated  soda 
solution  is  added  to  produce  a  pale  yellow  color. 
After  10  minutes  hydrochloric  acid  in  slight  excess  is 
run  in  and  the  free  iodine  titrated  with  sodium  thio- 
sulphate;  I2  =  HCHO.  This  method  cannot  be  used 
in  the  presence  of  other  aldehydes  or  of  acetone.  The 


1  Duprd,  Analyst,  I,  4  (1876);  Helmer,  Ibid.  12,  25  (1887). 

3  S.  J.  Lloyd,  J.  Am.  27, 16  (1905). 

8  Bernard  H.  Smith,  J.  Amer.  Chem.  Soc.  25,  1028  (1903). 

4  Z.  anal.  Chem.  38,  18  (1897). 


APPENDIX.  189 

" cyanide"  process  is  carried  out  as  follows:  Potassium 
cyanide  (6  grams  per  lit.)  is  added  in  some  excess  to  the 
aldehyde,  and  the  mixture  poured  into  o.iN  silver  nitrate 
solution  containing  so  much  nitric  acid  that  after  the 
mixing  the  liquid  remains  acid.  The  excess  of  cyanide 
separates  as  AgNC  and  the  silver  in  solution  is  titrated 
with  ammonium  thiocyanate  (Volhard's  method); 
KNC  =  HCHO.  This  process  can  be  used  in  the  presence 
of  acetaldehyde,  benzaldehyde,  or  acetone,  provided  that, 
in  the  first  case,  the  aldehyde-cyanide  mixture  is  added 
immediately  to  the  silver  nitrate. 


DETERMINATION  OF  FURFURALDEHYDE  AND  OF  PENTOSANS. 

The  additive  compound,  C9H8O5N2,  formed  from  fur- 
furaldehyde  and  barbituric  acid  (malonylcarbamide)  is 
useful  for  the  determination  of  this  aldehyde,1  and,  there- 
fore, for  the  analysis  of  pentosans.  This  method  offers 
advantages  over  the  use  of  phloroglucinol.  The  pre- 
cipitation is  made  in  hydrochloric  acid  solution  (12  per 
cent)  and  at  least  six  times  the  theoretical  quantity  of 
barbituric  acid  is  employed.  The  solubility  of  the  addi- 
tive compound  in  hydrochloric  acid  (12  per  cent)  is 
1.22  mgram.  in  100  cc. 

The  determination  of  furfuraldehyde  may  also  be 
carried  out  volumetrically.  The  pentose  (0.2-1.0  gram) 
is  heated  in  a  current  of  steam  with  hydrochloric  acid 
(sp.  gr.=  i.o6,  200  cc.).  During  the  course  of  the  dis- 
tillation more  acid  (100  cc.)  is  added.  An  aliquot  por- 

1  E.  linger  and  R.  Jager,  B.  36,  1222  (1903). 


1 9O  APPENDIX. 

tion  of  the  distillate  is  neutralized  with  aqueous  sodium 
hydroxide  (20  per  cent)  and  treated  with  potassium 
bisulphite,  in  excess.  After  about  2  hours  at  the  ordinary 
temperature  the  uncombined  bisulphite  is  titrated  with 
iodine  solution;  i  mol.  aldehyde  =i  mol.  KHSOs  =  l2; 
i  cc.  normal  bisulphite  =75. 05  mgram.  of  pentose.1 

The  well  known  method  of  Tollens  for  the  determi- 
nation of  pentosans  by  distillation  with  dilute  hydrochloric 
or  sulphuric  acid,  and  precipitation  of  the  resulting  furfur- 
aldehyde  by  means  of  phloroglucinol  has  been  further 
investigated.2  The  composition  of  the  precipitate  is 
CnH804.3 

One  source  of  error  in  the  determination  of  pentosans 
by  the  distillation  method  of  Tollens  is  due  to  the  pro- 
duction of  methylpentosans,  which  give  phloroglucides 
that  are  soluble  in  alcohol.  To  obviate  this  difficulty  the 
substance  is  distilled  in  the  ordinary  manner  with  hydro- 
chloric acid  (sp.  gr.=  i.o5)  and  phloroglucinol  added  to 
the  distillate.  The  precipitate  is  filtered,  washed,  dried, 
weighed,  and  extracted  with  alcohol  (95°  Tr.) ;  the 
residue  represents  the  pentosans.  The  alcoholic  extract 
can  be  evaporated  and  the  residue  weighed;  the  weight 
represents  the  methyl  derivatives  and  can  be  converted 
into  the  corresponding  values  of  rhamnose  by  means  of 
a  table.4  The  rhamnose  values  X  0.802  =  rhamnosan. 


1  Adolf  Jolles,  B.  39,  96  (1906). 

2  George  S.  Fraps,  Am.  Chem.  Journ.  25,  201  (1901);  Krober,  Journ. 
fur  Landw.  48,  357. 

3  W.  Goodwin  and  B.  Tollens,  B.  37,  315  (1904). 

«  W.  B.  Ellett  and  B.  Tollens,  Ibid.  38,  492  (1905). 


APPENDIX. 


DETERMINATION  OF    SCATOLE  AND   INDOLE. 

From  a  solution  containing  scatole,  indole  may  be 
precipitated  as  the  naphthoquinone  derivative  and  each 
of  the  substances  in  question  can  then  be  determined 
colorimetrically.1  In  the  case  of  indole  the  color  is  pro- 
duced by  sodium  /2-naphthaquinonesulphonate.2 


DETERMINATION   OF   DYES. 

The  use  of  titanium  trichloride  for  the  volumetric 
determination  of  a  number  of  dyes  which  form  colorless 
leuco-derivatives  has  been  extended  considerably.  It 
gives  good  results  with  indigo,  rhodamine  B,  pararosani- 
line  hydrochloride,  pararosanilinetrisulphonic  acid,  mala- 
chite green.,  crystal  violet,  tolusafranine,  indom,  and 
methylene  blue.3  Cf.  p.  183. 


DETERMINATION   OF    BINARY   MIXTURES   OF   THE   NITRANI- 
LINES.      Cf.  p.  l8l. 

The  composition  of  binary  mixtures  of  the  nitranilines 
may  be  determined  by  means  of  the  melting-point.  The 
melting-point  of  the  substance  under  examination  is 
determined  alone  and  also  when  mixed  with  some  of 
either  of  the  pure  isomers.  By  means  of  curves,  con- 

1  Christian  A.  Herter  and  M.  Louise  Foster,  J.  Biol.  Chem.  2,  267 
(1906). 

2  Ibid,  i,  257  (1906). 

3  Edmund  Knecht  and  Eva  Hibbert,  B.  38,  3318  (1905). 


I92  APPENDIX. 

structed  by  Bishop  Tingle  and  H.  F.  Rolker,  it  is  possible 

tv,  ~nd  the  composition  of  any  mixture  corresponding  to 
Uc  temperatures  observed.1 


DETERMINATION  OF  METHYLARSINE  DERIVATIVES. 

Methylarsine  diiodide,  CH3AsI2,  and  the  oxide, 
CH3AsO,  may  be  determined,  in  aqueous  solution,  by 
titration  with  iodine  dissolved  in  aqueous  potassium 
iodide.  The  reaction  takes  place  in  presence  of  acids 
and  results  in  the  production  of  hydriodic  acid  and 
methylarsenic  acid,  H3CAsO(OH)2.  It  is  probable  that 
the  method  is  applicable  to  compounds  containing 
radicles  other  than  methyl.2 


DETERMINATION  OF  HALOGENS. 

« 

The  determination  of  halogens  in  organic  compounds 
is  usually  effected  by  well  known  methods  which  result 
in  the  destructive  oxidation  of  the  remaining  elements 
that  are  present.  Such  processes  are  outside  the  scope 
of  this  volume  and  therefore  no  directions  •  concerning 
them  need  be  given.  The  method  described  below 
belongs  to  a  different  class.  The  substance  under  ex- 
amination is  weighed  into  a  reflux  apparatus,  heated  with 
alcohol  (98  per  cent,  20-40  cc.),  while  sodium  (50  atomic 
proportions)  is  dropped  in  small  pieces  down  the  con- 
denser tube.  Water  (20-40  cc.)  is  added  and  the  alcohol 


JJ.  Bishop  Tingle  and  H.  F.  Rolker,  Journ.  'Amer.  Chem.  Soc.   30, 
May,  1908. 

1  J.  Bougault,  Journ.  Pharm.  Chem.  [vi],  26,  193  (1907). 


APPENDIX. 


193 


distilled  off.  When  cold  the  residue  is  made  strongly 
acid  with  dilute  nitric  acid  and  the  halogen  titrated  by 
Volhard's  method.  The  process  has  been  applied  to 
chlor-  and  brombenzene,  ^-chlortoluene,  hexachlor- 
benzene,  and  bromnaphthalene.1 


DETERMINATION   OF   THIOPHENE. 

The  method  suggested  for  the  determination  of  thio- 
phene,  consisting  in  its  precipitation  from  benzene  solu- 
tion by  means  of  mercuric  acetate,2  appears  to  be  un- 
trustworthy.3 


1  A.  Stepanoff,  Journ.  Russ.  Phys.  Chem.  Soc.  37,  12  (1905). 
2O.  Dimroth,  B.  32,  759  (1899). 

3  Carl  Schwalbe,   Ibil.  38,   2208  (1905).     Cf.   C.   Liebermann  and 
B.  Pleus,  Ibid.  37,  2461  (1904). 


I94 


APPENDIX. 


WEIGHT    OF    A    CUBIC    CENTIMETER    OF    HYDROGEN 

PERATURE  OF   IO°-25°.1 

The  observed  height  of   the  barometer  is  reduced  to  o°  by 
and  2O°-25°  respectively. 


B  Height  of 
5  barom- 
3  eter. 

10°  C. 

mg 

n°  C. 

mg 

12°   C. 

mg 

13°  C. 
mg 

14°  C. 

mg 

15°  C. 
mg 

1  6°  C. 
mg 

i7'C. 

mg 

700 

0.07851 

0.07816 

0.07781 

0.07746 

0.077II 

0.07675 

0.07639 

0.07603 

702 

0.07874*0.078390.07804 

0.077690.07713  0.07697 

0.07661 

0.07625 

704 

0.07896  0.07861 

0.07826 

0.07791  0.07756  0.07720 

0.07684 

0.07647 

706 

0.07919  0.07884  0.07848 

0.07813  0.07778  0.07742  0.07706 

0.07670 

708 

0.0794210.07907  0.07871 

0.07836  0.07800  0.07774 

0.07729 

0.07692 

710 

0.07964  0.07929  0.07893 

0.07858  0.07823 

0.07787 

0.07750 

0.07714 

712 

0.07987,0.07952  0.07917 

0.07881  0.07845 

0.07809  0.07772 

0.07736 

716 

0.08009  0.07975  0-07939 
0.08032  0.07997  0.07961 

0.07903  10.07808  '0.07832  '0.07  795 
0.07924(0.07890  0.07854  0.07817 

0.0/759 
0.07781 

718 

0.08055  0.08019  0.07984 

0.07948  0.07912 

0.07876  0.07840 

0.07803 

720 

0.08078  0.08043  0.08007 

0.07971  0.07935  0.07899  0.07862 

0.07825 

722 

0.08101 

0.08065  o  08029 

0.07993  0.07957 

0.07921 

0.07884 

0.07847 

724 

0.08123  0.08087  0.08052 

0.08016 

0.079790.07943 

0.07907 

0.07869 

726    0.081460.081100.08074 

0.08038  0.08002  0.07965 

0.07929 

o  07891 

728 

0.08169  o>o&133  0.08097 

0.08061  0.08024 

0.07987 

0.07951 

0.07913 

730 

0.08191 

0.08156  O.O8I2O 

0.08083 

0.08047  O.oSoiO 

0.07973 

0.07936 

732 

O.o82i5'o.o8i79  0.08142 

O.o8io6!o.o8o69  0.08032  0.07995 

0.07958 

734  ;o.o8237  0.08201 

0.08164 

0.08129  0.08091 

o.o8o55!o.o8oiS 

0.07980 

736 

o.o8259'o.o8224  0.08187 

0.08151  0.08114 

0.08077  0.08040 

O.C8OO2 

738    0.08282  0.08246  0.08209 

0.08173 

O.o8i36jo.o8o99(o.o8o62  0.08024 

740   0.08305 

0.08269  0.08233 

0.08196 

0.08158 

o.o8i22'o.oSo84  0.08047 

742  10.08328 

0.08291  0.08255 

0.08218 

0.08181 

0.08144  0.08106  0.08069 

744    0.08351 

0.08314  0.08277 

0.08240 

0.08203 

0.08166  0.08129  0.08091 

746    0.08373  0.08337  0.08300 

0.08263 

0.082260.081890.08151  0.08113 

748    0.083960.083600.08322 

0.08285 

0.08248,0.08211 

0.08173  0.08135 

750 

0.08419  0.08382  0.08344 

0.08308 

0.08270  0.08234  0.0819510.08158 

752 

0.08441 

0.084040.08368 

0.08331 

0.08293  0.08256  0.08218  0.08180 

754 

0.08464 

0.08428  0.08390 

0.08353  0.08315  0.08278 

0.08240  O.O82O2 

756 

0.08487 

o  084500.08413 

0.08376  0.08338  0.08301 

0.08262  0.08224 

758 

0.08510.0.08472 

0.08435 

0.08398 

0.08360  0.08323  0.08285  0.08246 

760 

0.085330.08496 

0.08458 

0.08420  o.o83820.o8345'o.o8307  0.08269 

762 

0.08555 

0.08518 

0.08481 

0.08443 

0.08405 

0.08367 

0.08329  0.08291 

764 

0.08578 

0.08541 

0.08503 

0.08465 

o  08428 

0.08389  0.08352  0.08313 

766 

0.08601 

0.08563 

0.08525  0.08487 

0.08450 

0.08412 

0.083740.08335 

768 

0.08624 

0.08586 

o.o8549!o.o85ii 

0.08473 

0.08434:0.08396 

0.08357 

770 

0.08646 

0.08608 

0.08571  0.08533 

0.08495 

0.08466  0.08418  0.08380 

J  A.  Baumann,  Z.  ang.  Ch.  1891,  210. 


APPENDIX. 


195 


UNDER    A   PRESSURE   OF  700-770  MM   AND    AT    A   TEM- 
f  ^-^0.089523  \ 
760(1  -f-  0.003660  J' 
subtracting   I,  2,  or  3  mm  for  the  temperatures  io°-i2°,  I3°-I9°, 


i8°C. 
mg 

I9°c. 

mg 

20°  C. 

mg 

21°  C. 

mg 

22°  C. 

mg 

23°  c. 

mg 

24°  C. 
mg 

25°  C. 
mg 

„  Height  of 
g  barom- 
B  eter. 

0.07557 

0.07529 

0.07493 

0.07455 

0.07417 

0.07380 

0.07340 

0.07300 

700 

0.07588 

0.07552 

0.07515 

0.07477 

0.07439 

0.07401 

0.07362 

0.07322 

702 

0.07610 

o  07574 

0.07537 

0.07499 

0.07461 

0.07422 

0.07383 

0.07344 

704 

0.07633 

0.07595 

0.07559 

0.07521 

0.07483 

0.07444 

0.07405 

0.07366 

706 

0.07655 

0.07618 

0.07581 

0.07543 

0.07505 

0.07466 

0.07427 

0.07387 

708 

0.07677 

0.07640 

0.07603 

0.07565 

0.07527 

0.07487 

0.07449 

0.07409 

710 

0.07699 

0.07662 

0.07625 

0.07587 

0.07548 

0.07509 

0.07470 

0.07431 

712 

0.07722 

0.07684 

0.07646 

0.07608 

0.07570 

0.07531 

0.07492 

0.07452 

714 

0.07743 

0.07706 

0.07668 

0.07630 

0.07592 

0-07553 

0.07513 

0.07473 

716 

0.07765 

0.07728 

0.07690 

0.07652 

0.07614 

0.07574 

0.07535 

0.07495 

718 

0.07788 

0.07749 

0.07712 

0.07674 

0.07635 

0.07596 

0.07550 

0.07516 

720 

0.07809 

0.07772 

0-07734 

0.07696 

0.07657 

0.07618 

0.07577 

0.07538 

722 

0.07831 

0.07794 

0.07756 

0.07718 

0.07679 

0.07640 

0.07609 

0.07560 

724 

0.07854 

0.07816 

0.07778 

o  07740 

0.07701 

0.07661 

0.07621 

0.07582 

726 

0.07876 

0.07838 

0.07800 

0.07762 

0.07723 

0.07683 

0.07643 

0.07604 

728 

0.07908 

0.07860 

0.07822 

0.07784 

0.07744 

0.07705 

0.07665 

0.07624 

730 

0.07920 

0.07882 

0.07844 

0.07805 

0.07766 

0.07727 

0.07687 

0.07646 

732 

0.07942 

0.07904 

0.07866 

0.07827 

0.07780 

0.07748 

0.07708 

0.07668 

734 

0.07964 

0.07926 

0.07888 

0.07849 

0.07810 

0.07770 

0.07730 

0.07689 

736 

0.07986 

0.07948 

0.07916 

0.07871 

0.07831 

0.07792 

0.07752 

0.07711 

738 

0.08009 

0.07970 

0.07932 

0.07893 

0.07853 

0.07813 

0.07774 

0.07732 

740 

0.08030 

0.07992 

0.07954 

0.07915 

0.07875 

0.07835 

0.07795 

0.07754 

742 

0.08053 

0.08014 

0.07976 

0.07937 

0.07897 

0.07857 

0.07817 

0.07776 

744 

0.08075 

0.08036 

0.07998 

0.07959 

0.07919 

0.07879 

0.07838 

0.07797 

746 

0.08097 

0.08058 

O.o8O2O 

o  07981 

0.07940 

0.07900 

0.07860 

0.07819 

748 

0.08119 

0.08080 

0.08042 

0.08002 

0.07962 

0.07922 

0.07881 

0.07840 

750 

0.08141 

0.08102 

0.08063 

0.08024 

0.07984 

0.07944 

0.07903 

0.07862 

752 

0.08163 

0.08124 

0.08085 

0.08046 

0.08006 

0.07966 

0.07925 

0.07883 

754 

0.08185 

0.08146 

0.08107 

0.08068 

0.08028 

0.07987 

0.07947 

0.07905 

756 

0.08207 

0.08168 

0.08129 

0.08090 

0.08050 

0.08009 

0.07968 

0.07927 

758 

0.08229 

0.08190 

0.08151 

0.08112 

0.08071 

0.08031 

0.07990 

0.07949 

760 

0.08251 

.08212 

0.08173 

0.08134 

0.08093 

0.08052 

O.O8OI2 

0.07970 

762 

0.08273 

.08234 

0.08195 

0.08155 

0.08115 

0.08074 

0.08033 

0.07992 

764 

0.08295 

.08256 

0.08217 

0.08177 

0.08137 

0.08096 

0.08055 

0.08013 

766 

0.08318 

.08278 

0.08239 

0.08199 

0.08158 

0.08118 

0.08076 

0.08034 

768 

0.08341 

.08301 

0.08261 

0.08221 

O.o8l8o 

0.08139 

0.08098 

0.08056 

770 

196  APPENDIX. 

TENSION  OF  AQUEOUS  VAPOR. 


0°C. 

mm 

o°C. 

mm 

10.  0 

9.165 

18.0 

15-357 

10.5 

9-474 

18.5 

15.845 

II.  0 

9-792 

19.0 

16.346 

ii.  5 

IO.  I2O 

19-5 

16.861 

12.  0 

10-457 

20.  o 

17.391 

12.5 

10.804 

20.5 

17-935 

13-0 

II.I62 

21.  0 

18.495 

13-5 

11.530 

21-5 

19.069 

14.0 

I  I  .  908 

22.0 

19.659 

14-5 

12.298 

22-5 

20.  265 

15-0 

12.699 

23.0 

20.888 

15-5 

13.  112 

23-5 

21.528 

16.0 

I3-536 

24.0 

22.184 

16.5 

13-972 

24-5 

22.858 

17.0 

14.421 

25.O 

23-550 

17-5 

14.882 

TABLE  FOR  THE  VALUE  OF 


•1000  —  a 


.  a  =  I  —  a  =  999. 


0 

i 

* 

3 

4 

5 

6 

7 

8 

9 

00 

or 

02 

03 
04 

0.0000 
101 

204 

309 
417 

OIO 

III 

215 

320 
428 

O2O 
122 

225 
331 

438 

030 
132 
235 
341 

449 

O4O 
142 
246 

352 
460 

050 
152 
256 
363 
471 

060 
I63 
267 

373 

V482 

071 

173 
278 
384 

493 

08  1 

183 

288 

395 
504 

Ogi 
194 

299 
406 

515 

05 
06 
07 
08 
09 

526 
638 

753 
0.0870 
989 

537 
650 

764 

881 

*OOI 

549 
66  1 

776 

893 
*oi3 

560 
672 

788 
905 

*025 

57i 
684 

799 
917 
*038 

582 
695 

811 

929 
*oso 

593 
707 
823 
941 

*062 

605 
718 
834 
953 
*074 

616 
730 
846 

965 
*o87 

627 

741 
858 

977 
*o99 

10 

II 

12 
13 
14 

O.  IIII 

236 

364 

494 
628 

124 
249 
377 
508 
641 

136 

261 
390 

528 
655 

148 

274 
403 

534 
669 

151 
287 
416 

547 
682 

173 
299 
429 
564 
696 

186 
312 
442 

574 
710 

198 
325 

455 
588 

723 

211 

338 
468 
60  1 

737 

223 
35i 
481 
614 
75i 

15 

16 

17 

18 

19 

765 
905 
0.2048 
195 
346 

779 
919 
083 

2IO 

361 

793 
933 
077 
225 
376 

806 

947 
092 
240 
392 

820 
962 
107 
255 
407 

834 
976 

121 

270 
422 

848 
990 
136 
285 
438 

862 
*oos 

151 
300 

453 

877 
*oi9 
1  66 
315 
469 

891 
*034 
1  80 
33i 
484 

i  Obach— Ostwald,  Z.  II.  566. 


APPENDIX. 


197 


TABLE  FOR  THE  VALUE  OF 


.      (Continued.') 


0 

i 

2 

3 

4 

5 

6- 

7 

8 

9 

20 

21 
22 
23 
24 

o.  2500 

658 
821 
987 
0.3158 

5i6 
674 

837 
*oo4 

175 

531 
690 

854 

*O2I 
193 

547 
707 
870 
*o38 

2IO 

563 
723 

887 

*o55 

228 

579 
739 
903 

*072 

245 

595 
755 
920 
*o89 
263 

610 

771 

937 
*io6 
280 

626 
788 
953 

*I23 

298 

642 

804 
970 
*I4I 
316 

25 
26 

27 

28 

29 

333 
5i4 
699 
889 
0.4085 

35i 
532 
717 
908 
104 

369 
550 
736 
928 
124 

387 
569 

755 
947 
144 

405 
587 
774 
967 
164 

423 
605 

793 
986 
184 

441 
624 
812 
*oo6 
205 

459 
643 

831 

*025 

225 

477 
661 
850 
*Q45 
245 

495 
680 
870 
*o65 
265 

30 
31 
32 

33 
34 

286 

493 
706 

925 
0.5152 

306 

5M 
728 
948 
175 

327 

535 
749 
970 
198 

347 
556 
771 
993 

221 

365 
577 
793 
*oi5 
244 

389 
599 
8i5 
*o38 
267 

409 
620 

837 
*o6o 
291 

430 
641 
859 

*o83 
314 

45i 
663 
881 
*io6 

337 

472 
684 
903 

*I29 

361 

35 
36 
37 
38 
39 

385 
625 
873 
0.6129 

393 

408 
650 
898 
155 
420 

432 
674 
924 
181 

447 

456 
699 

949 
208 

475 

480 
721 
974 
234 
502 

504 
748 

*000 

260 

529 

528 
773 

*026 

287 
556 

552 
798 
*o5i 
313 

584 

576 
813 
*077 
340 
6n 

601 
848 
*i63 
367 
639 

40 
4i 
42 
43 
44 

667 

949 
0.7241 

544 

857 

695 
978 
271 

575 
889 

722 
*oo7 
301 
606 
921 

750 
*o36 
33i 
637 
953 

779 
*o65 
361 
668 
986 

807 

*o94 

39i 
699 
*oi8 

835 

*I23 

422 

731 

*osi 

863 
*i53 
452 
762 
*o83 

892 

*l82 

483 
*794 
116 

921 

*2I2 

513 

825 

*I49 

45 
46 

47 
48 
49 

0.8182 

519 
868 
0.9231 
608 

215 
553 
904 
268 
646 

248 
587 
939 
305 
685 

282 
622 
975 
342 
724 

315 
657 
*on 
380 
763 

349 
692 
*o48 
418 
802 

382 

727 
*o84 

455 
841 

416 

762 

*I2I 

493 

881 

450 
797 
*i57 
53i 
920 

484 
832 
*I94 
570 
960 

50 

51 
52 
53 
54 

I.  000 

041 
083 
128 
174 

004 
045 

088 
132 
179 

008 
049 
092 
137 
183 

012 

053 
096 
141 

188 

016 

058 

IOI 

146 
193 

020 

062 
105 
151 
198 

024 

066 
no 
155 
203 

028 
070 
114 
1  60 

208 

033 
075 
119 
165 

212 

037 
079 
123 
169 
217 

55 
56 

57 
58 
59 

222 

273 
326 
381 

439 

227 
278 
331 
387 
445 

232 
283 
336 
392 
45i 

237 
288 
342 
398 

457 

242 
294 
347 
404 

463 

247 
299 
353 
410 
469 

252 
304 

358 
415 
475 

257 
309 
364 
421 
484 

262 

315 
370 
427 
488 

268 
320 
375 
433 
494 

198  APPENDIX. 

TABLE  FOR  THE  VALUE  OF   - 


looo  —  a 


.     {Continued.) 


o 

i 

2 

3 

4 

5 

6 

7 

8 

9 

60 

61 
62 

63 
64 

1.500 

564 
632 
703 

778 

506 
571 
639 
710 

786 

513 

577 
646 

717 
793 

519 

584 

653 

725 

801 

525 
591 
660 

732 
809 

532 

597 
667 
740 
817 

538 
604 
674 

747 

825 

545 
611 
681 

755 
833 

55i 
618 
688 
762 

841 

556 
625 
695 
770 
849 

65 
66 
67 
68 
69 

857 
941 
2.030 
125 
226 

865 
950 
040 
135 
236 

874 
959 
049 

145 

247 

882 
967 
058 
155 
257 

890 
976 
067 
165 
268 

899 
985 
077 
175 
279 

907 

994 
086 

185 
289 

*915 
*oo3 

096 
195 
300 

924 

*OI2 

106 
205 
3ii 

933 

*O2I 
H5 
215 
322 

70 

7i 
72 

73 
74 

75 
76 
77 
78 
79 

80 

81 
82 

83 
84 

85 
86 

87 
88 
89 

333 
448 

57i 
704 
846 

3.000 
167 
348 
545 
762 

4.000 
263 
556 
882 
5-250 

344 
460 

584 
717 
861 

016 

184 

367 

566 

785 

025 
291 

587 
917 
289 

356 
472 
597 
73i 
876 

367 
484 
610 

745 

891 

378 

497 
623 

759 
906 

390 
509 
636 

774 
922 

401 
521 
650 
788 
937 

413 
534 
663 
802 
953 

425 
546 
676 
817 
968 

132 
310 
505 
7i7 
950 

436 

559 
690 

831 
984 

149 

329 
525 
739 
975 

236 

525 

848 

*2II 
623 

032 
202 

386 
587 
808 

049 
219 

405 
608 

831 

065 
237 
425 
630 

854 

082 
255 
444 
651 
878 

098 

274 
464 

673 
902 

US 
292 

484 
695 
926 

051 
319 
618 
952 
329 

076 

348 
650 
988 
369 

IO2 
376 
682 
*024 

410 

128 
405 
714 
*o6i 
452 

155 
435 
747 
"098 

494 

181 

465 

780 

*I35 
536 

208 
495 
814 

*I73 
579 

667 
6.143 
692 

7-333 
8.091 

7ii 
194 

752 
403 
174 

757 
246 

813 
475 
259 

803 
299 
874 
547 
346 

849 

353 
937 
621 

434 

897 

407 
*ooo 
696 
524 

944 

463 
*o65 
772 
615 

993 
519 
*I3O 
850 
769 

*042 

576 
*I97 
929 
804 

*092 
654 

*264 
*OO9 
901 

90 
9i 
92 
93 
94 

9.000 

10.  II 

11.50 
13.29 
15-67 

101 

10-33 
11.66 

13-49 
15-95 

204 
10.36 
11.82 

I3.7I 
16.24 

309 
10.49 
11.99 

13.93 
16.54 

417 
10.63 
12.  16 
14.15' 
i6.86| 

526 
10.77 
12.33 
14-38 
17.18 

638 
10.90 
12.51 
14.63 
17-52 

753 
11.05 
12.70 
14.87 
17.87 

870 

11.20 
12.89 

15.13 
18.23 

989 
H-35 
13  08 
15-39 
18.61 

95 
96 

97 
98 
99 

19.00 
24.00 

32.33 
49.00 
99.0 

19.41 
24.64 
33-48 
51.6 
no 

19-83 
25.32 
34-71 
54-6 
124 

20.28 
26.03 
36.04 
57-8 
142 

20.74! 
26.78 
37.46 
61.5 
166 

21.22  21.73 
27.57  28.41: 
39.0040.67 

65.7  J70.4 
199  J  249 

22.26 
29-30 
42.48 
75-9 
332 

22.81 
30.25 

44-45 
82.3 
499 

23-39 
31.26 
46.62 
89.9 
999 

INDEX. 

NOTE. — The  names  of  authors  are  printed  in  italics. 


PAGE 

Acetic  acid 4 

glacial 6,     10 

anhydride 6,  8,  10,  112 

Acetylation,  methods  of 6,  95,  97,  98,   106,   112,   143,   147,   148 

Acetyl  bromide 6,  8 

chloride  .  .  . .' 6,  9 

derivatives,  isolation 10,  144 

preparation 6,  143 

groups,  determination 1 1 

additive  method 18 

distillation  method 19 

hydrolytic  method 1 1,  144 

potassiam  acetate  method 18 

hydroxamic  chloride,  reagent  for  amines 175 

number 139 

value 139 

Acids,  determination  by  indirect  methods 48,  58 

electrolytic  conductivity 48,  53 

esterification 48,  51,  159 

salts 48,  49 

titration 48,  50,  1 59 

Acylation 4,  30,  143,  174 

Albitzky,  A 8,  1 2 

Albumoses,  separation 171 

Albuminoid  compounds,  separation 171 

199 


200  INDEX. 

PAGE 

Aldehydes,  vide  carbonyl  compounds 68,  161 

derivatives 1 66 

Aldoximes 80 

Aliphatic  amine  groups,  determination 95 

diazo  compounds 1 20 

titration  with  iodine 1 20 

Alkaloids,  titration pS 

Alkylation 4,  108,  149,  177 

of  hydroxyl  groups 31,  149 

Alkyl  groups,  determination 114  et  seq. 

Alkylmagnesium  halides,  reagents  for  hydroxyl 152 

Allen,  A.  H 136 

C 53 

Allyl  group,  determination 167 

Altmann,  P 129 

Amido  groups,  determination no,  179 

Amines,  acetylation 106,  1 74,  1 79 

•alkylation 108,  177 

salts 95,  97,  105 

separation  of  primary  and  secondary 177 

Amino  acids,  isolation 1 70,  171 

/>-Aminodimethylaniline  derivatives 68,  92 

Amino  group,  aliphatic 95,  169 

aromatic 97,  172 

determination 95,  no,  169 

Aminoguanidine  bicarbonate 91 

derivatives 68,  90 

picrate  derivatives 88,  92 

salts 90 

Ammonia,  hydrolysis  by 11,14 

A  nderlini 5,  69 

A ngeli,  A.  .  .  . .' 104 

Anschutz,  R 52 

Aqueous  vapour,  tension 144 

Armstrong,  E.  F 8 

Aromatic  amino  compounds,  acylation 98,  174 

diazo  derivatives 97,  99 

salts  of 97,  98,  172 

groups,  determination 95,  97,  172 

diazo  compounds 1 20,  1 23 

Askenasy,  P 135 


INDEX.  2OI 

PAGE 

Astruc,  A 51,  159 

Auwers,  K » .  .33,  81,  no,  151 

Azo  dyes 97,  99,  172 

group  determination 183 

Azoimide  method  for  determination  of  amino  group 98,  102 


B 

Baeyer,  A .  v 84,  87,  90,  106,  136 

Bakunin,  M 33 

Qalbiano,  L 168 

Bamberger,  E 23,  70,  73,  82,  123 

M 6,  41,  44 

Barbier,  Henri 1 74 

Barium  hydroxide,  hydrolysis  by 1 1 ,  13 

salts  in  carbonyl  determination 68,  93 

Barth 14,  24 

Barus 54 

Basicity  of  acids,  determination  by  ammonia 48,  58,  59 

carbonates 48,  58 

electrolytic  conductivity 48,  53 

etherification 48,  51 

hydrogen  sulphide 48,  58,  60 

iodine 48,  58,  64 

salts 48,  49 

titration 48,  50 

Baum,  E 71,  83,  149 

Baumann 4,  22,  24,  32,  64,  66,  142 

Bcckmann,  E 10,  36,  47,  148 

Behrens,  G.  H 153 

Benedikt • 5,  12,  40,  41,  44,  74,  78,  136 

Benzene  and  water,  tension 77 

sulphonic  chloride 107 

Behzoic  acid  .  . 4 

acids,  substituted 4 

anhydride 21,  25 

Benzoyl  chloride 21 

derivatives,  analysis 28,  -148 

preparation 21,  147 

Benzyl  derivative" 4,  32 

phenylhydrarine,  in  carbonyl  determination 74,  161 


202  INDEX. 

PAGE 

Berthelot,  D 57 

Biddle 173 

Biginelli 83 

Biltz,  Heinrich 180 

Blau,  Fr 96 

Boeris 119 

Borsche,  W 165 

Bougault,  J 192 

Bouveault,  Louis no,  in,  164,  165 

Bou'dler,  W.  A 53 

Brauchbar 6 

Brener,  R 88 

Bristol,  H.  Stanley 174 

/>-Brombenzenesulphonic  chloride 107 

/>-Brombenzoic  anhydride 21,  26,  27 

0-Brombenzoyl  chloride 21,  26,  27 

/>-Brombenzoyl  chloride 21,  26,  27 

/>-Bromphenylhydrazine 72 

Bruhl,  J.W 148 

Bruyn,  L.  de 74 

Buchka 19 

Bulow,  C 1 06 

Busch,  M 118,  158 


C 

Cahart , 58 

Cahn,  A 92 

Cain 109 

Cajar,  H 84 

Calcium  carbonate,  hydrolysis  by 1 1,  14 

Cameron,  A 1 49 

Carbamates 4 

preparation 33,  34 

Carbamyl  chloride,  preparation 33 

Carbonyl,  determination 68,  161 

hydrolysis 167 

phenylhydrazine 68,  161 

substituted  phenylhydrazines 68,  161 

indirect  method 68,  74,  163 


INDEX.  203 

PAGE 

Carboxyl,  determination 38,  48,  1 59 

by  electrolytic  conductivity  .  .  .  <• 48,  53 

esterification 48,  51 

salt  analysis 48,  49 

titration 48,  50,  159 

indirect 48 

by  ammonia 48,  58,  59 

carbonates 48,  58 

hydrogen  sulphide 48,  58,  60 

iodine 48,  58,  64 

Carter,  W 53 

Caspari,  W.  A 36 

Causse,  H 1 29 

Cavazzi 104 

Chalk,  hydrolysis  by n,  14 

Chaperon 54 

Charante,  J .  M.  van 47 

Chloracetyl  chloride 6,  10 

i-2-4-Chlordinitrobenzene 37 

p-Chlorphenyhydrazifte 74 

Ciamician 16,  18,  119 

Claisen,  L 7,  25,  27,  144,  161,  164 

Claus 83,  no 

Clauser,  R 132,  182 

Clowes,  G.  H.  A 94 

Cohen,  E 54>  55 

Cullie,  N 49,  106 

Copper,  reagent  for  amino  group 104 

Crismer 83 

Cuprous  chloride,  reagent  for  amino  group 103,  1 23 

Curtius,  T 84,  93,  103,  120,  121,  122,  127 


D 

Danckworth 1 2,  22 

Da-vies 83 

Davis,  S 25 

Decker,  Hermann 149,  156,  158,  177,  181 

Dedichen 103 

Deinert,  J no 

De  la  Harpe 99,  1 1 2 


204  INDEX. 

PAGE 

Delepine 97 

Deninger,  A 7,  25 

Diamant,  J 9 

Diazo  compounds,  aliphatic 1 20 

aromatic 99,  1 20,  1 23 

preparation 99,  1 01 

group,  determination 1 20  et  seq. 

methane,  reagent  for  hydroxyl 32 

method  for  determination  of  nitro  group 132 

Diazonium  derivatives 1 20,  1 23 

Dibromphenylhydrazine 74 

Dieckmann,  W 143,  151 

tw-Diiodophenylhydrazine 74 

Dimethyl  sulphate,  reagent  for  hydroxyl 32,  108 

Dimroth,  0 193 

Diphenylcarbamyl  chloride,  preparation 34 

reagent  for  hydroxyl 150 

Diphenylhydrazine 74 

Dooriner,  P 21 

Dupr'e 1 88 

Dyes,  determination 191 


E 

Ebert 57 

Eckart,  U 37 

Eckenslein,  A .  van 74 

Eckhardt 49 

Eckstein,  0 148 

Effront,  J 1 70 

Ehm-ann,  L 41 

Ehrlich 5 

Eibner,  A 107 

Einhorn,  Alfred 7,  23,  25,  93,  174 

Elbers 7° 

Electrolytic  conductivity  of  sodium  salts 53 

Ellett,  W.B 190 

Ephraim 70 

Erb 109,  no 

Erdmann,  E 13,  19,  34,  100 

Erk  . .  19 


INDEX.  205 

/  PAGE 

Etard,  A 147 

Esterification  of  acids 48,  51,  159 

Etherification  of  phenols • 33 

Ethoxyl  and  methoxyl,  differentiation 47 

determination 38,  48 

Ethyl  alcohol,  determination 187,  188 

Ethylene  group  in  amines,  determination 168 

E^hylimine  and  methylimine,  differentiation 119 

determination 95,119 


F 

Fauts,  R 48 

Federer,  Max 162 

Feist,  F 7,  25,  73 

Feit 83 

Feiller 104 

Fenner,  G 106 

Fischer,  E -.8,  23,  52,  69,  70,  71,  73,  107,  108,  113 

Formaldehyde,  determination 186,  188 

Partner 31 

Foster,  M.  Louise 191 

Franchimont 9 

Franzen,  H 151 

Fraps,  George  S 190 

Fresenius 19 

Freund,  M 52,  88,  89 

Freyss,  G 9 

Friedlander,  P 14 

Frobenius 1 23 

Fuchs,  F . .  60,  64 

Fulda,  H.  L 51 

Furfuraldehyde,  determination 189 


G 

Ganzert,  R 70 

Garelli 82 

Gattermann,  L 33,  34,  70,  104,  in,  132 

Gattermann  Sandmeyer's  reaction 98,  103 


206  INDEX. 

PAGE 

Georgescu,  M 28 

Gersenheimer,  H 52 

Ghiro 5 

Ginsberg,  Alexander 168 

Glrand,  H 113 

Glasmann,  Boris 169,  181 

Gnehm,  Robert 158,  186 

Goldschmidt 158 

Goldschmidt,  H 37,  1 23 

Goldschmiedt 14,  18,  21,  24,  26,  35,  58,  59,  158 

Goodwin,  W 1 50,  190 

Gordin,  H.M 98 

Graebe,  C 5,  14,  32,  160 

Grandmougin 103 

Green,  A.  G 102 

Gregor,  J 6   67 

Griess,  P 102 

Grignard's  reagent,  for  hydroxyl 152 

Grimaldi,  Siro 167 

Groger,  M 67 

Grotoivsky,  H 106 

Grussner 40 

Grumpert 36 

Guyot : 33 


H 

Haase,  E 144 

Hagen  ,,, 52,  53 

Haitinger 50 

Hatter 33 

Halogens,  determination 192 

Hantzsch 1 10,  1 23 

Hanus,  Jos 184 

Harpe,  De  la 99,  1 1 2 

Harries,  C 84 

Hartmann,  E 147 

Hauers,  R 161 

Hawkins 102 

Heidenrich,  K 84 

Heller,  Gustav 174,  180 


INDEX.  207 

PAGE 

Helmer, 188 

Hemmelmayr 18,  21,  26,  59,  70 

Henrigues,  R 136 

Herter,  Christian  A 191 

Herzfeld 16,  92 

Herzig,  J 6,  9,  13,  19,  32,  44,  52,  83,  114,  118,  119 

Herzog,  J 1 50 

Hesse,  G 101 

Heuser 85 

Hewitt,  J.G 157 

Heyl,  G in 

Hibbert,  Eva 191 

Hibberl,  Harold 1 53,  1 77 

Hilger,  A 74,  162 

Hinsberg,  0 27,  31,  170,  179 

Hinterlach,  E 165 

Hirsch,  R 100 

Hoffmann,  A.W 35,  105,  109 

C 83 

E .r 24,    25 

Hollandt,  F 7,  23,  25 

Holle 70 

Hollemann „ 125 

Holmes,  John 187 

Homolka 49,  81 

Honigschmid,  0 1 58 

Hopkins,  E 136 

Hormann,  G 4,  9 

Hubl 136 

Huth 34 

Hyde,  E 73 

Hydrazide  group,  determination 1 20,  125 

by  iodine 125,  127 

Hydrazides,  oxidation 125 

reagents  for  carbonyl 92,  93 

Hydrazones,  substituted,  preparation , 73 

Hydriodic  acid,  hydrolysis  by 1 1,  16 

Hydrochloric  acid,  hydrolysis  by n,  15,  109 

Hydrogen,  weight  of  a  cc „ 194 

Hydrolytic  methods  for  determination  of  acetyl n,  144 

benzoyl 28,  148 


208  INDEX. 

PAGE 

Hydroxyl,  determination 4,  143 

Hydroxylamine,  reagent  for  carbonyl 68,  80 

hydrochloride 80 


I 

Imbert,  H 51 

Imidogen,  elimination  as  ammonia 113 

Imines,  acetylation 1 1 2,  180 

alkylation 113,  180 

salts 113,  180 

Imino  group,  determination 95,  112,  180 

Introduction : i 

Iodine  number 120,  136,  184 

lodo  derivatives  of  aliphatic  diazo  compounds 1 20,  121 

/>-Iodophenylhydrazine 74 

Indole,  determination i  QI 

lodoso  group,  determination 1 20,  134 

lodoxy  group,  determination 1 20,  134 

Iritzer,  S 1 25,  1 29 

Irvine,  J .  C 149 

losbutyric  acid 4 

anhydride 30 

Isobutyryl  derivatives 31 


J 

Jackson,  F.  L 27 

Jacobson,  P 33,  92,  109,  112 

Jaffe,  M 24 

Jager,  R 189 

Jahoda,  R 21 

Janny 80 

Jassoy 3 l 

Jeaneraud 8  < 

Jekn,  C 50 

Jenssen 1 29 

Jolles,  Adolf 19° 

Jones,  E.  M.  Chapman 109 

H 54 

Just..                                              7° 


INDEX.  209 

K 

PAGE 

Kahl,    Richard 165 

Kahn,  Robert 159 

Kanitz,  Aristides 159 

' Kaserer,  H 52 

Kaufler,  Felix 158,  186 

Kehrmann 82,  83,  106 

Kenzon, 1 74 

Kerp,  W 90 

Kessler,  J 179 

Ketones,  vide  carbonyl  compounds 68,  161 

hydrazine  derivatives  of 165 

derivatives 1 56 

Ketoximes 81 

Kinnicutt,  L.  P 102 

Klimont,  J 139 

Klobukowsky 10,  13 

Knecht,  Edmund  .  .« 184,  191 

Knikelin,  F 53 

Knoevenagel 1 23 

Knop 65 

Knorr,  E 8,  13 

L 3°,  36>  5i 

Koch,  0 149 

Koenigs,  W * 8,  13 

Kohlrausch 55,  57 

Kohn 6 

Kormann,  W 96 

Kostanecki 32,  82,  144 

Kraus 73 

Kropatscher,  W : 158 

Krober 190 

Kr'uger 73,  87 

Kunnc,  H 136 

Kux 64 

L 

La  Coste 9 

Ladenburg no 

•v.  Lamt>e 144 

Lander,  G.  D 149 


210  INDEX. 

PAGE 

Landsiedl 6 

Lapworth,  A 109 

Lassar-Cohn 49 

Lehmann,  F 84 

Lewkowitsch,  J 136,  137,  139 

Lieben 12,  14,  50 

Liebermann,  C 4,  9,  16,  25,  52,  53,  193 

Limpricht,  H 129 

Lloyd,  S.  J 188 

Locquin,  Rene 161,  164,  165 

Lossen 4,  22,  23 

Lucas 1 10 

Lumiere,  Auguste 174 

Louis 1 74 


M 

Magnesia,  hydrolysis  by 1 1,  14 

Magnesium  alkyl  compounds 37 

Manasse,  A 171 

Marchlewsk'i 23,  32 

Marckwald,  W 107 

Marquenne,  L 9,  150 

McKenzie,  A 149 

Mcllhiney,  P.  C 60 

Mehner,  H 124 

Meissler,  A 37 

Meldola 102 

Mendius no 

Menschutkin,  N 98,  177 

Mentzel.  Curt -. 1 66 

Merkwitz,  C 165 

M erz,  A 1 23 

.Methods,  miscellaneous 185 

Methoxyl,  determination  (Ziesel's  method) 38 

modified 40,  45,  46,  154 

in  presence  of  methylimide 117 

differentiation  from  ethoxyl 47 

Methyl  alcohol,  determination 186 

Methylarsine  derivatives,  determination 192 

.Methyiene,  determination 94 


INDEX.  211 

PAGE 

Methylimine  and  ethylimine,  differentiation up 

determination 95,  114,  180 

determination  in  presence  of  methoxyl 117 

Methylphenylhydrazine,  reagent  for  carbonyl 74,  162 

Metzner,  H 31 

Meyenburg,  F.v 8 1 

Meyer 49 

E.v 127 

H 20,  29,  44,  64,  114,  118,  119,  126,  159,  160 

R 20,  29,  70,  147 

V 24,  25,  33,  51,  70,  71,  80,  83,  92,  109,  no,  in,  112,  135 

Michael,  A 148 

Michael,  H.  A 9,  20,  72,  84 

Michaelis 72 

Michel,  0 103 

Micklethwait 174 

Miller,  W.v 53 

Monopyrocatecholcarbonic  hydrazide 93 

Moore,  G.  S 157 

Morgan 174 

Muhlhausen,  G 166 

Munch 1 10 

Munson,  L.  S 184 

Munchmeyer 70 

Murco,  H 159 


N 

/?-Naphthalenesulphonic  chloride 108 

/?-Naphthylphenylhydrazine,  reagent  for  carbonyl 74 

Nef,  J.  U 70,  71,  83,  102 

Neuberg,  C 71,  74,  89,  162,  163,  171 

Neudorfer,  J 14 

Neufeld,  A 74 

Neugebauer,  E.  L in 

Neumann,  W 89 

Nietzki 82 

Nitranilines,  determination 181,  191 

Nitrile  group,  determination 95,  108 

Nitriles,  hydrolysis 109 

jw-Nitrobenzenesulphonic  chloride 107 


212  INDEX. 

PAGE 

Nitrobenzhydrazide 92 

w-Nitrobenzoyl  chloride 21,27 

Nitrogen,  determination  in  aliphatic  diazo  compounds 120,  121 

Nitro  group,  determination 1 20,  129,  181,  191 

by  diazo  method 132 

titration 1 29 

/?-Nitrophenylhydrazine 73 

Nitrosobenzhydrazide 93 

Nitroso  group,  determination 120,  132,  182 

Nitrous  acid,  reagent  for  amino  group 95 

Nolting 103 


O 

Obach 144 

CEnanthaldehyde,  reagent  for  amino  group 95,  97 

Ofner,  R 163 

Ollendorff,  G 74 

Opianic  acid 30 

Osazones 71 

Ostwald,  W .53,  55,  144 

Otto 27 

Overton,  B 69,  72 

R 74 

Oximes,  preparation 80,  163 


P 

Panormow 22 

Paolini,  V 168 

Passmore,  F 7° 

Patterson 58 

Pawleu-ski,  B 107 

Pechmann,  v 22,  32,  70,  123,  135 

Pentosans,  determination 189 

Peptones,  separation I71 

Perkin,  A.  G 32,  144,  145,  146 

W.H 49>  143,  IS1*  J54 

Peroxide  group,  determination 1 20,  135 

Petersen 125,  1 27 

Petraczek 80 


INDEX.  213 

PAGE 

Petrenko-Kritschenko,  P , 173 

Phenol,  determination , j88 

Phenols,  esterincation „ 33 

separation 1$-$ 

Phenylactic  acid 4 

Phenylacetyl  chloride ?0,  3  r 

Phenylcarbamates 4,  35 

Phenylcarbamic  acid  derivatives,  preparation 4,  3^  150 

Phenylhydrazine,  reagent  for  carbonyl 68,  161 

substituted 74,  161 

Phenylhydrazones,  preparation 68,  161 

substituted,  preparation 68,  72,  73,  161 

/?-Phenylhydroxylamine,  reagent  for  aldehydes 164 

Phenylisocyanate,  action  on  hydroxyl 35,  1 50 

preparation 35 

Phenylsulphonic  acid 4 

chloride 21,  27,  107 

Phosphoric  acid 19 

derivatives 31 

Phosphorus  oxychloride 7 

trichloride 7 

Piccinini,  Galeazzo 164 

Pickard,  R.  H 53,  174 

Pictet 173 

Pinnoiv,  J 106 

Pitkeathly,  W 149 

Plancher,  Guiseppe 164 

Pleus,  B 193 

Pomernnz 44 

Potassium  hydroxide,  hydrolysis  by 1 1,  12,  109 

hydroxylamine  sulphonate 80,  82 

Prettner,  August 174 

Pribram 47 

Primary  amines,  separation  from  secondary 177 

Propenyl  group,  determination 167 

Propionic  acid 4 

anhydride 30 

Propionyl  derivatives 31 

Prud'homme,  M 108 

P schorr,  R 18 

Pum,  G 28,  44 


214  INDEX. 

PAGB 

Pummerer,  Rudolf 1 73 

Punier 5 

Purdie,  T 149 

Pyromucyl  chloride,  reagent  for  hydroxyl 148 


R 

Radziszewsky no 

Raschig 82 

Regnault 1 23 

Reissert,  Arnold 175 

Reverdin 99,  1 1 2 

Reychler,  A 58 

Richards,  T.W 51 

Rideal,  S 102 

Roesler,  Armand 169 

Rolfe,  G.W 27 

Rolker,  H.  F 181,  192 

Romijn 188 

Rossolimo,  A.  J 177 

Roser 175 

Rothenfusser,  S 74,  162 

Ruff,  0 74 

Rupe,  Hans 165 

S 

Sachsse,  R 96 

Salts  of  acids,  analysis 49 

bases 98,  105,  113,  164,  173 

Sandmeyer 103 

-Gattermann's  reaction 98,  103 

Sarauiv 5 

Saul,  E 70 

Scatole,  determination 191 

Schall 19 

Schander,  A 88,  89 

Schelling,  R.  v 51 

Schiaparelli,  C 28 

Schiff,  Hugo 6,  14,  18,  97,  1 70 

Schlocho/,  Paul 165 


INDEX.  215 

PAGE 

Schlomann 26,  27 

Schmidt,  G 33 

Schmiedeberg .• 49 

Schmoeger 16 

Scholz,  M 74 

Schopf 26 

Schotten 4,  24,  26,  27,32 

Schreder 24 

Schultz 13,  19 

Schunk 23,  32 

Sctiiitzenberger 16 

Schwalbe,  Carl 173,  193 

Schweitzer,  G 182 

Secondary  amines,  separation  from  primary 177 

Sedgwick.  A.  P 49 

Seelig 6,  71,  80,  82 

Semicarbazine  hydrochloride,  preparation 86 

reagent  for  carbonyl 68 

salts,  preparation 84 

sulphate  preparation 87,  164 

Semicarbazones,  preparation 84,  87,  164 

Semioxamazine,  preparation 90 

Semmler,  F.W 166 

Seybold,  W 160 

Siegfried,  M 1 70,  172 

Silber 16 

Simonsen,  J.  L 151 

Sisley,  P 20 

Skraup •. 22,  23,  31 

Smith,  Alex 49 

A.W 81 

Bernard  H 188 

Watson 163 

Snape 35,  36 

Sodium  acetate 6,  8 

benzoate 21,  25 

hydroxide,  hydrolysis  by 1 1,  12,  109 

Solonina,  B 1 56 

W 107 

Speier 52 

Spindler 1 29 


2l6  INDEX. 

PACE 

Stallburg 109 

Stamogler,  F 173 

Stange,  O 85,  86 

Stannic  chloride 9 

Stearic  anhydride 30 

Stepanoff,  A 193 

Stein,  R 143,  151 

Stillich,  0 143 

Strache,  H 74,  78,  125.  1 29 

Striiar,  Milan  J 1 57,  186 

Stronhal 54 

Substituted  benzoic  acids 26 

acylation  by  .  . . 27 

phenylhydrazones,  preparation 73,  74 

Sudborough,  J.  J 26,  109,  no,  in,  146,  153,  177 

Sulphuric  acid,  hydrolysis  by n.  16,  no.  in,  144 

Swain,  R.  E 1 29,  1 74 


T 

Tables 194  et  seq. 

Table  for  value  of 196 

looo  —  a 

of  tension  of  benzene  and  water 77 

water 196 

weight  of  "a  cc.  of  hydrogen 194 

Tafel,  J 7X»  lo6 

Tenile 9 

Terebenthene  number 139 

Tessmer 36 

Tetrabromphenylhydrazine 74 

Thiacetic  acid  as  acetylating  agent 107 

Thiele 84,  85,  86,  90 

Thiophene,  determination 193 

Thiosemicarbazine  derivatives,  preparation 88 

Thomas,  W - 146 

Thompson 27 

Thorns 7° 

Thorp,  F.H 81 

Thorpe,  J.  F M3 

Thorpe,  Thomas  Edward 187 


INDEX.  217 

PAGE 

Tickle,  T 1 06 

Tiemann,  F 73,  81,  82,  8;,.88 

Tingle,  A '..  .52,  71,  83,  163 

J.  Bishop 52,  71,  84,  181,  192 

Titanium  chloride,  reagent 181,  183,  191 

Titherley,  Arthur  Walsh 1 79 

Titration  of  acids 48,  50,  159 

TollenSy  B 161,  190 

Tolman,  L.  M 184,  185 

^-Toluenesulphonic  chloride 107 

esters 149 

5-Tribromphenylhydrazine 74 

Tschugae/,  L 37 


U 

Ullmann,  F 32,  108,  149 

Ulzer -. 12 

Unger,  E 189 

K 90 

V 

Valeur 9 

Vanino,  L 135 

Vila,  A 147 

Villiger,  V 106,  136 

Vohl 59 

Volhard 47,  81,  137 

Vongerichten 30,  37 

Vondracek,  R 161,  162 

Vortmann 13 

Votocek,  Emil .  , 161,  162 

Vries,  de 125 

W 

Wachter 135 

Wagner 65 

Walden,  P 53,  106 

Walker,  A.  J 33,  no 

Wallbaum no 


21 8  INDEX. 

PAGE 

Walter,  R 132 

Water  and  benzene,  table  of  tension 77 

hydrolysis  by 11,12 

table  of  tension 196 

Wedel,  J 70 

Wegscheider 1 160 

Wenner,  P 32,  108,  149 

Wenzel,  F 16 

Werner,  A .160,  174 

Wheeler,  Henry  L 1 74 

Wiedemann 57 

Wieland,  Heinrich 1 50,  1 76 

Wijs,  J.  J.  A 137,  184 

Willgerodt 135 

Willstatter,  Richard 173 

Wislicenus 7,  18,  37,  70 

Wohl 80 

Wolff 92 

Wright 12 


Y 
Young,  S.W 129 

Z 

Zanoli 35 

Zeidler,  H 186 

Zeisel,  S 2,  12,  14,  32,  38,  44,  45,  48,  83 

Zeitschel,  O 101 

Zelinsky,  A7. 88 

Zinc  chloride 9 

dihydroxylamine  hydrochloride,  reagent  for  carbonyl 80,  83 

Zincke,  Th 166 


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Whipple's  Microscopy  of  Drinking-water 8vo,  3  50 

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Elliott's  Engineering  for  Land  Drainage I2mo,  i  50 

Practical  Farm  Drainage i2mo,  i  oo 

*Fiebeger's  Treatise  on  Civil  Engineering 8vo,  5  oo 

Folwell's  Sewerage.     (Designing  and  Maintenance.) 8vo,  3  oo 

Freitag's  Architectural  Engineering.     2d  Edition,  Rewritten 8vo,  3  50 

French  and  Ives's  Stereotomy 8vo,  2  50 

Goodhue's  Municipal  Improvements i2rro,  i  73 

Goodrich's  Economic  Disposal  of  Towns'  Refuse 8vo,  3  50 

Gore's  Elements  of  Geodesy 8vo,  2  50 

Hayford's  Text-book  of  Geodetic  Astronomy 8vo,  3  oo 

Bering's  Ready  Reference  Tables  (Conversion  Factors) i6mo,  morccco,  2  50 

5 


Howe's  Retaining  Walls  for  Earth i2mo,  i  25 

Johnson's  (J.  B.)  Theory  and  Practice  of  Surveying Small  8vo,  4  oo 

Johnson's  (L.  J.)  Statics  by  Algebraic  and  Graphic  Methods 8vo,  2  oo 

Laplace's  Philosophical  Essay  on  Probabilities.    (Truscott  and  Emory.) .  12 mo,  2  oo 

Mahan's  Treatise  on  Civil  Engineering.     (1873.)     (Wood.) 8vo,  5  oo 

*  Descriptive  Geometry 8vo,  i  50 

Merriman's  Elements  of  Precise  Surveying  and  Geodesy 8vo,  2  50 

Elements  of  Sanitary  Engineering 8vo,  2  oo 

Merriman  and  Brooks's  Handbook  for  Surveyors i6mo,  morocco,  2  oo 

Nugent's  Plane  Surveying 8vo,  3  50 

Ogden's  Sewer  Design i2mo,  2  oo 

Patton's  Treatise  on  Civil  Engineering 8vo  half  leather,  7  50 

Reed's  Topographical  Drawing  and  Sketching 4 to,  5  oo 

Rideal's  Sewage  and  the  Bacterial  Purification  of  Sewage 8vo,  3  50 

Siebert  and  Biggin's  Modern  Stone-cutting  and  Masonry 8vo,  i  50 

Smith's  Manual  of  Topographical  Drawing.     (McMillan.) 8vo,  2  50 

Sondericker's  Graphic  Statics,  with  Applications  to  Trusses,  Beams,  and  Arches. 

8vo,  2  oo 

Taylor  and  Thompson's  Treatise  on  Concrete,  Plain  and  Reinforced 8vo,  5  oo 

*  Trautwine's  Civil  Engineer's  Pocket-book i6mo,  morocco,  5  oo 

Wait's  Engineering  and  Archi  ectural  Jurisprudence 8vo,  6  oo 

Sheep,  6  50 

Law  of  Operations  Preliminary  to  Construction  in  Engineering  and  Archi- 
tecture  8vo,  5  oo 

Sheep,  5  50 

Law  of  Contracts 8vo,  3  oo 

Warren's  Stereotomy — Problems  in  Stone-cutting 8vo,  2  50 

Webb's  Problems  in  the  Use  and  Adjustment  of  Engineering  Instruments. 

i6mo,  morocco,  i   25 

*  Wheeler  s  Elementary  Course  of  Civil  Engineering 8vo,  4  oo 

Wilson's  Topographic  Surveying 8vo,  3  50 

BRIDGES  AND  ROOFS. 

Boiler's  Practical  Treatise  on  the  Construction  of  Iron  Highway  Bridges.  .  STO,  2  oo 

*  Thames  River  Bridge 4to,  paper,  5  oo 

Burr's  Course  on  the  Stresses  in  Bridges  and  Roof  Trusses,  Arched  Ribs,  and 

Suspension  Bridges 8vo,  3  50 

Burr  and  Falk's  Influence  Lines  for  Bridge  and  Roof  Computations.  .  .  .8vo,  3  oo 

Du  Bois's  Mechanics  of  Engineering.     Vol.  II Small  4to,  10  oo 

Foster's  Treatise  on  Wooden  Trestle  Bridges 4to,  5  oo 

Fowler's  Ordinary  Foundations 8vo,  3  50 

Greene's  Roof  Trusses 8vo,  i  25 

Bridge  Trusses 8vo,  2  50 

Arches  in  Wood,  Iron,  and  Stone. 8vo,  2  50 

Howe's  Treatise  on  Arches 8vo,  4  oo 

Design  of  Simple  Roof-trusses  in  Wood  and  Steel 8vo,  2  oo 

Johnson,  Bryan,  and  Turneaure's  Theory  and  Practice  in  the  Designing  of 

Modern  Framed  Structures Small  4to,  10  oo 

Merriman  and  Jacoby's  Text-book  on  Roofs  and  Bridges: 

Part  I.     Stresses  in  Simple  Trusses 8vo,  2  50 

Part  H.     Graphic  Statics 8vo,  2  50 

Part  HI.     Bridge  Design 8vo,  2  50 

Part  IV.'    Higher  Structures , 8vo,  2  50 

Morison's  Memphis  Bridge 4to,  10  oo 

Waddell's  De  Pontibus,  a  Pocket-book  for  Bridge  Engineers.  .  i6mo,  morocco,  3  oo 

Specifications  for  Steel  Bridges i2mo.  i  25 

Wood's  Treatise  on  the  Theory  of  the  Construction  of  Bridges  and  Roofs .  .  8vo,  2  CO 
Wright's  Designing  of  Draw-spans : 

Part  I.     Plate-girder  Draws. 8vo,  2  50 

Part  II.     Riveted-truss  and  Pin-connected  Long-span  Draws 8vo,  2  50 

Two  parts  in  one  volume 8vo,  3  5° 

6 


HYDRAULICS. 

Bazin's  Experiments  upon  the  Contraction  of  the  Liquid  Vein  Issuing  from 

an  Orifice.     (Trautwine.) 8vo,  2  oo 

Bovey's  Treatise  on  Hydraulics 8vo,  5  oo 

Church's  Mechanics  of  Engineering 8vo,  6  oo 

Diagrams  of  Mean  Velocity  of  Water  in  Open  Channels paper,  i  50 

Coffin's  Graphical  Solution  of  Hydraulic  Problems i6mo,  morocco,  2  50 

Flather's  Dynamometers,  and  the  Measurement -of  Power *. i2mo,  3  oo 

FolwelPs  Water-supply  Engineering 8vo,  4  oo 

Frizell's  Water-power 8vo,  5  oo 

Fuertes's  Water  and  Public  Health i2mo,  i  50 

Water-filtration  Works i2mo,  2  50 

Ganguillet  and  Kutter's  General  Formula  for  the  Uniform  Flow  of  Water  in 

Rivers  and  Other  Channels.     (Hering  and  Trautwine.) 8vo,  4  oo 

Hazen's  Filtration  of  Public  Water-supply 8vo,  3  oo 

Hazlehurst's  Towers  and  Tanks  for  Water-works 8vo,  2  50 

Herschel's  115  Experiments  on  the  Carrying  Capacity  of  Large,  Riveted,  Metal 

Conduits 8vo,  2  oo 

Mason's  Water-supply.     (Considered  Principally  from  a  Sanitary  Standpoint.) 

8vo,  4  oo 

Merriman's  Treatise  on  Hydraulics 8vo,  5  oo 

*  Michie's  Elements  of  Analytical  Mechanics 8vo,  4  oo 

Schuyler's   Reservoirs  for  Irrigation,   Water-power,   and   Domestic   Water- 
supply Large  8vo,  5  oo 

**  Thomas  and  Watt's  Improvement  of  Rivers.     (Post.,  440.  additional.). 4to,  6  oo 

Turneaure  and  Russell's  Public  Water-supplies 8vo,  5  oo 

Wegmann's  Design  and  Construction  of  Dams 4to,  5  oo 

Water-supply  of  the  City  of  New  York  from  1658  to  1895 4to,  10  oo 

Williams  and  Hazen's.Hydraulic  Tables 8vo,  i  50 

Wilson's  Irrigation  Engineering Small  8vo,  4  oo 

Wolff's  Windmill  as  a  Prime  Mover 8vo,  3  oo 

Wood's  Turbines 8vo,  2  50 

Elements  of  Analytical  Mechanics 8vo,  3  oo 

MATERIALS  OF  ENGINEERING. 

Baker's  Treatise  en  Masonry  Construction 8vo,  5  oo 

Roads  and  Pavements 8vo,  5  oo 

Black's  United  States  Public  Works Oblong  4to,  5  oo 

Bovey's  Strength  of  Materials  and  Theory  of  Structures 8vo,  7  50 

Burr's  Elasticity  and  Resistance  of  the  Materials  of  Engineering 8vo,  7  50 

Byrne's  Highway  Construction 8vo,  5  oo 

Inspection  of  the  Materials  and  Workmanship  Employed  in  Construction. 

i6mo,  3  oo 

Church's  Mechanics  of  Engineering 8vo,  6  oo 

Du  Bois's  Mechanics  of  Engineering.     Vol.  I Small  4to,  7  50 

*Eckel's  Cements,  Limes,  and  Plasters 8vo,  6  oo 

Johnson's  Materials  of  Construction Large  8vo,  6  oo 

Fowler's  Ordinary  Foundations 8vo,  3  50 

Keep's  Cast  Iron 8vo,  2  50 

Lanza's  Applied  Mechanics 8vo,  7  50 

Marten's  Handbook  on  Testing  Materials.     (Henning.)     2  vols 8vo,  7  50 

Merrill's  Stones  for  Building  and  Decoration 8vo,  5  oo 

Merriman's  Mechanics  of  Materials.                                  8vo,  5  oo 

Strength  of  Materials I2mo,  i  oo 

Metcalf's  Steel.     A  Manual  for  Steel-users i2mo,  2  oo 

Patton's  Practical  Treatise  on  Foundations 8vo,  5  oo 

Richardson's  Modern  Asphalt  Pavements '. 8vo,  3  oo 

Richey's  Handbook  for  Superintendents  of  Construction i6mo,  mor.,  4  oo 

Rockwell's  Roads  and  Pavements  in  France i2mo,  i  23 

1 


Sabin's  Industrial  and  Artistic  Technology  of  Paints  and  Varnish 8vo,  3  oo 

Smith's  Materials  of  Machines i2mo,  i  oo 

Snow's  Principal  Species  of  Wood .  .  . 8vo,  3  50 

Spalding's  Hydraulic  Cement 121110,  2  oo 

Text-book  on  Roads  and  Pavements i2mo,  2  oo 

Taylor  and  Thompson's  Treatise  on  Concrete,  Plain  and  Reinforced 8vo,  5  oo 

Thurston's  Materials  of  Engineering.     3  Parts 8vo,  8  oo 

Part  I.     Non-metallic  Materials  of  Engineering  and  Metallurgy 8vo,  2  oo 

Part  II.     Iron  and  Steel 8vo,  3  50 

Part  III.     A  Treatise  on  Brasses,  Bronzes,  and  Other  Alloys  and  their 

Constituents 8vo,  2  so 

Thurston's  Text-book  of  the  Materials  of  Construction 8vo,  5  oo 

Tillson's  Street  Pavements  and  Paving  Materials 8vo,  4  oo 

WaddelTs  De  Pontibus.    ( A  Pocket-book  for  Bridge  Engineers.).  .  i6mo,  mor.,  3  oo 

Specifications  for  Stt .  i  Bridges i2mo,  i  25 

Wood's  (De  V.)  Treatise  on  the  Resistance  of  Materials,  and  an  Appendix  on 

the  Preservation  of  Timber 8vo,  2  oo 

Wood's  (De  V.)  Elements  of  Analytical  Mechanics 8vo,  3  oo 

Wood'o  (M.  P.)  Rustless  Coatings:    Corrosion  and  Electrolysis  of  Iron  and 

Steel 8vo,  4  oo 

RAILWAY  ENGINEERING. 

Andrew's  Handbook  for  Street  Railway  Engineers 3x5  inches,  morocco,  i  25 

Berg's  Buildings  and  Structures  of  American  Railroads 4to,  5  oo 

Brook's  Handbook  of  Street  Railroad  Location i6mo,  morocco,  i  50 

Butt's  Civil  Engineer's  Field-book i6mo,  morocco,  2  50 

Crandall's  Transition  Curve i6mo,  morocco,  i  50 

Railway  and  Other  Earthwork  Tables 8vo,  i  50 

Dawson's  "Engineering"  and  Electric  Traction  Pocket-book.  .  i6mo,  morocco,  5  oo 

Dredge's  History  of  the  Pennsylvania  Railroad:   (1879) Paper,  5  oo 

*  Drinker's  Tunnelling,  Explosive  Compounds,  and  Rock  Drills. 4to,  half  mor.,  25  oo 

Fisher's  Table  of  Cubic  Yards Cardboard,  25 

Godwin's  Railroad  Engineers'  Field-book  and  Explorers'  Guide.  .  .  i6mo,  mor.,  2  50 

Howard's  Transition  Curve  Field-book i6mo,  morocco,  i  50 

Hudson's  Tables  for  Calculating  the  Cubic  Contents  of  Excavations  and  Em- 
bankments  8vo,  i  oo 

Mo  liter  and  Beard's  Manual  for  Resident  Engineers i6mo,  i  oo 

Nagle's  Field  Manual  for  Railroad  Engineers i6mo,  morocco,  3  oo 

Philbrick's  Field  Manual  for  Engineers i6mo,  morocco,  3  oo 

Searles's  Field  Engineering i6mo,  morocco,  3  oo 

Railroad  Spiral. i6mo,  morocco,  i  50 

Taylor's  Prismoidal  Formulae  and  Earthwork 8vo,  i  50 

*  Trautwine's  Method  of  Calculating  the  Cube  Contents  of  Excavations  and 

Embankments  by  the  Aid  of  Diagrams 8vo,  2  oo 

The  Field  Practice  of  Laying  Out  Circular  Curves  for  Railroads. 

>,        I2mo,  morocco,  2  50 

Cross-section  Sheet Paper,  25 

Webb's  Railroad  Construction i6mo,  morocco,  5  oo 

Wellington's  Economic  Theory  of  the  Location  of  Railways Small  8vo,  5  oo 

DRAWING. 

Barr's  Kinematics  of  Machinery 8vo,  2  50 

*  Bartlett's  Mechanical  Drawing 8vo,  3  oo 

*  "                    "                   "        Abridged  Ed 8vo,  i  50 

Coolidge's  Manual  of  Drawing 8vo,  paper  i  oo 

Coolidge  and  Freeman's  Elements  of  General  Drafting  for  Mechanical  Engi- 
neers  -. Oblong  4to,  2  50 

Durley's  Kinematics  of  Machines 8vo,  4  oo 

Emch's  Introduction  to  Projective  Geometry  and  its  Applications 8vo.  2  50 

8 


Hill's  Text-book  on  Shades  and  Shadows,  and  Perspective 8vo,  2  oo 

Jamison's  Elements  of  Mechanical  Drawing 8vo,  2  50 

Advanced  Mechanical  Drawing 8vo,  2  oo 

Jones's  Machine  Design: 

Part  I.     Kinematics  of  Machinery 8vo,  i  50 

Part  n.     Form,  Strength,  and  Proportions  of  Parts 8vo,  3  oo 

MacCord's  Elements  of  Descriptive  Geometry 8vo,  3  oo 

Kinematics;  or,  Practical  Mechanism 8vo,  5  oo 

Mechanical  Drawing fc 4to,  4  oo 

Velocity  Diagrams 8vo,  i  50 

*  Mahan's  Descriptive  Geometry  and  Stone-cutting 8vo,  i  50 

Industrial  Drawing.     (Thompson.) 8vo»  3  50 

Moyer's  Descriptive  Geometry 8vo,  2  oo 

Reed's  Topographical  Drawing  and  Sketching 4to,  5  oo 

Reid's  Course  in  Mechanical  Drawing 8vo,  2  oo 

Text-book  of  Mechanical  Drawing  and  Elementary  Machine  Design. 8vo,  3  oo 

Robinson's  Principles  of  Mechanism 8vo,  3  oo 

Schwamb  and  Merrill's  Elements  of  Mechanism 8vo,  3  oo 

Smith's  Manual  of  Topographical  Drawing.     (McMillan.) 8vo, 


Warren's  Elements  of  Plane  and  Solid  Free-hand  Geometrical  Drawing.  i2mo, 

Drafting  Instruments  and  Operations 12010., 

Manual  of  Elementary  Projection  Drawing i2mo, 

Manual  of  Elementary  Problems  in  the  Linear  Perspective  of  Form  and 

Shadow i2mo, 

Plane  Problems  in  Elementary  Geometry i2mo. 


50 
oo 
25 
5» 

oo 
25 

Primary  Geometry i2mo,  .  75 

Elements  of  Descriptive  Geometry,  Shadows,  and  Perspective 8vo,  3  50 

General  Problems  of  Shades  and  ^shadows 8vo,  3  oo 

Elements  of  Machine  Construction  and  Drawing 8vo,  7  50 

Problems,  Theorems,  and  Examples  in  Descriptive  Geometry 8vo,  2  50 

Weisbach's  Kinematics  and  Power  of  Transmission.    (Hermann  and  Klein)8vo,  5  oo 

Whelpley's  Practical  Instruction  in  the  Art  of  Letter  Engraving 12 mo,  2  oo 

Wilson's  (H.  M.)  Topographic  Surveying 8vo,  3  50 

Wilson's  (V.  T.)  Free-hand  Perspective 8vo,  2  50 

Wilson's  (V.  T.)  Free-hand  Lettering 8vo,  i  oo 

Woolf's  Elementary  Course  in  Descriptive  Geometry. Large  8vo,  3  oo 


ELECTRICITY  AND  PHYSICS. 

Anthony  and  Brackett's  Text-book  of  Physics.     (Magie.) Small  8vo,  3  oo 

Anthony's  Lecture-notes  on  the  Theory  of  Electrical  Measurements.  .  .  .I2mo,  i  oo 

Benjamin's  History  of  Electricity. 8vo,  3  oo 

Voltaic  Cell 8vo,  3  oo 

Classen's  Quantitative  Chemical  Analysis  by  Electrolysis.     (Boltwood.).Svo,  3  oo 

Crehore  and  Squier's  Polarizing  Photo-chronograph 8vo,  3  oo 

Dawson's  "Engineering"  and  Electric  Traction  Pocket-book.  i6mo,  morocco,  5  oo 
Dolezalek's   Theory   of   the    Lead   Accumulator    (Storage    Battery).      (Von 

Ende.) i2mo,  2  50 

Duhem's  Thermodynamics  and  Chemistry.     (Burgess.) 8vo,  4  oo 

Flather's  Dynamometers,  and  the  Measurement  of  Power 12010,  3  oo 

Gilbert's  De  Magnete.     (Mottelay.) 8vo,  2  50 

Hanchett's  Alternating  Currents  Explained i2mo,  I  oo 

Hering's  Ready  Reference  Tables  (Conversion  Factors) i6mo,  morocco,  2  50 

Holman's  Precision  of  Measurements 8vo,  2  oo 

Telescopic   Mirror-scale  Method,  Adjustments,  and   Tests.  .  .  .Large  8vo,  75 

Kinzbrunner's  Testing  of  Continuous-Current  Machines. 8vo,  2  oo 

Landauer's  Spectrum  Analysis.     (Tingle.) 8vo,  3  oo 

Le  Chatelien's  High-temperature  Measurements.  (Boudouard — Burgess.)  i2mo.  3  oo 

Lob's  Electrolysis  and  Electrosynthesis  of  Organic  Compounds.  (Lorenz.)  i2mo,  i  oo 


*  Lyons's  Treatise  on  Electromagnetic  Phenomena.  Vols.  I.  and  II.  8vo,  each,    6  oo 

*  Michie's  Elements  of  Wave  Motion  Relating  to  Sound  and  Light 8vo,    4  oo 

Niaudet's  Elementary  Treatise  on  Electric  Batteries.     (Fishback.).  ....  i2mo, 

*  Rosenberg's  Electrical  Engineering.     (Haldane  Gee — Kinzbrunner.).  .  .8vo, 

Ryan,  Norris,  and  Hoxie's  Electrical  Machinery.     Vol.  1 8vo, 

Thurston's  Stationary  Steam-engines 8vo, 

*  Tillman's  Elementary  L«ssons  in  Heat 8vo, 

Tory  and  Pitcher's  Manual  of  Laboratory  Physics Small  8vo, 

Ulke's  Modern  Electrolytic  Copper  Refining 8vo,    3  oo 

LAW. 

*  Davis's  Elements  of  Law 8vo,    2  50 

*  Treatise  on  the  Military  Law  of  United  States 8vo,    7  oo 

Sheep,  7  50 

Manual  for  Courts-martial i6mo,  morocco,  i  50 

Wait's  Engineering  and  Architectural  Jurisprudence 8vo,  6  oo 

Sheep,  6  50 

Law  of  Operations  Preliminary  to  Construction  in  Engineering  and  Archi- 
tecture  8vo,  5  oo 

Sheep,  5  50 

Law  of  Contracts 8vo,  3  oo 

Winthrop's  Abridgment  of  Military  Law I2mo,  2  50 

MANUFACTURES. 

Bernadou's  Smokeless  Powder — Nitro-cellulose  and  Theory  of  the  Cellulose 

Molecule i2mo,  2  50 

Bolland's  Iron  Founder i2mo,  2  50 

"  The  Iron  Founder,"  Supplement i2mo,  2  50 

Encyclopedia  of  Founding  and  Dictionary  of  Foundry  Terms  Used  in  the 

Practice  of  Moulding i2mo,  3  oo 

Eissler's  Modern  High  Explosives 8vo,  4  oo 

Effront's  Enzymes  and  their  Applications.     (Prescott.).  .  .  . 8vo,  3  oo 

Fitzgerald's  Boston  Machinist i2mo,  i  oo 

Ford's  Boiler  Making  for  Boiler  Makers i8mo,  i  oo 

Hopkin's  Oil-chemists'  Handbook 8vo,  3  oo 

Keep's  Cast  Iron 8vo,  2  50 

Leach's  The  Inspection  and  Analysis  of  Feod  with  Special  Reference  to  State 

Control. Large  8vo,  7  50 

Matthews's  The  Textile  Fibres 8vo,  3  50 

Metcalf's  Steel.     A  Manual  for  Steel-users i2mo,  2  oo 

Metcalfe's  Cost  of  Manufactures — And  the  Administration  of  Workshops  8vo,  5  oo 

Meyer's  Modern  Locomotive  Construction 4to,  10  oo 

Morse's  Calculations  used  in  Cane-sugar  Factories i6mo,  morocco,  i  50 

*  Reisig's  Guide  to  Piece-dyeing 8vo,  25  oo 

Sabin's  Industrial  and  Artistic  Technology  of  Paints  and  Varnish 8vo,  3  oo 

Smith's  Press-working  of  Metals 8vo,  3  oo 

Spalding's  Hydraulic  Cement i2mo,  2  oo 

Spencer's  Handbook  for  Chemists  of  Beet-sugar  Houses.    ...  i6mo,  morocco,  3  oo 

Handbook  for  Sugar  Manufacturers  and  their  Chemists.  .  i6mo,  morocco,  2  oo 

Taylor  and  Thompson's  Treatise  on  Concrete,  Plain  and  Reinforced 8vo,  5  oo 

Thurston's  Manual  of  Steam-boilers,  their  Designs,  Construction  and  Opera- 
tion  8vo,  5  oo 

*  Walke's  Lectures  on  Explosives 8vo,  4  oo 

Ware's  Manufacture  of  Sugar.     (In  press.) 

West's  American  Foundry  Practice I2mo,    2  50 

Moulder's  Text-book i2mo,    2  50 

10 


Wolff's  Windmill  as  a  Prime  Mover 8vo,    3  oo 

Wood's  Rustless  Coatings:   Corrosion  and  Electrolysis  of  Iron  and  Steel.  .8vo,    4  00 


MATHEMATICS. 

Baker's  Elliptic  Functions 8vo,    I  5* 

*  Bass's  Elements  of  Differential  Calculus lamo,    4  oo 

Briggs's  Elements  of  Plane  Analytic  Geometry .• i2mo, 

Compton's  Manual  of  Logarithmic  Computations I2mo, 

Davis's  Introduction  to  the  Logic  of  Algebra 8vo, 

*  Dickson's  College  Algebra Large  i2mo, 


*  Introduction  to  the  Theory  of  Algebraic  Equations Large  xamo, 

Emch's  Introduction  to  Projective  Geometry  and  its  Applications 8vo, 

Halsted's  Elements  of  Geometry 8vo, 

Elementary  Synthetic  Geometry , 8vo, 

Rational  Geometry i2mo, 

*  Johnson's  (J.  B.)  Three-place  Logarithmic  Tables:   Vest-pocket  size. paper,  15 

100  copies  for  5  oo 

*  Mounted  on  heavy  cardboard,  8X 10  inches,  25 

10  copies  for  2  oo 

Johnson's  (W.  W.)  Elementary  Treatise  on  Differential  Calculus .  .SmahSvo,  3  oo 

Johnson's  (W.  W.)  Elementary  Treatise  on  the  Integral  Calculus. Small  8 vo,  i  50 

Johnson's  (W.  W.)  Curve  Tracing  in  Cartesian  Co-ordinates i2mo,  i  oo 

Johnson's  (W.  W.)  Treatise  on  Ordinary  and  Partial  Differential  Equations. 

Small  8vo,  3  50 

Johnson's  (W.  W.)  Theory  of  Errors  and  the  Method  of  Least  Squares  i2mo,  i  50 

*  Johnson's  (W.  W,)  Theoretical  Mechanics I2mo,  3  oo 

Laplace's  Philosophical  Essay  on  Probabilities.     (Truscott  and  Emory.) .  i2mo,  2  oo 

*  Ludlow  and  Bass.     Elements  of  Trigonometry  and  Logarithmic  and  Other 

Tables 8vo,  3  oo 

Trigonometry  and  Tables  published  separately Each,  2  oo 

*  Ludlow's  Logarithmic  and  Trigonometric  Tables 8vo,  i  oo 

Maurer's  Technical  Mechanics 8vo,  4  oo 

Merriman  and  Woodward's  Higher  Mathematics.  , 8vo,  5  oo 

Merriman's  Method  of  Least  Squares .    .8vo,  2  oo 

Rice  and  Johnson's  Elementary  Treatise  on  the  Differential  Calculus. .  Sm.  8vo,  3  oo 

Differential  and  Integral  Calculus.     2  vols.  in  one Small  8vo,  2  50 

Wood's  Elements  of  Co-ordinate  Geometry 8vo,  2  oo 

Trigonometry:  Analytical,  Plane,  and  Spherical i2mo,  i  oo 


MECHANICAL  ENGINEERING. 

MATERIALS  OF  ENGINEERING,  STEAM-ENGINES  AND  BOILERS. 

Bacon's  Forge  Practice i2mo,  50 

Baldwin's  Steam  Heating  for  Buildings i2mo,  50 

Barr's  Kinematics  of  Machinery 8vo,  50 

*  Bartlett's  Mechanical  Drawing. . 8vo,  oo 

*  "  "  "        Abridged  Ed 8vo,         50 

Benjamin's  Wrinkles  and  Recipes i2mo,        oo 

Carpenter's  Experimental  Engineering 8vo,     6  oo 

Heating  and  Ventilating  Buildings 8vo,    4  oo 

Gary's  Smoke  Suppression  in  Plants  using  Bituminous  Coal.     (In  Prepara- 
tion.) 

Clerk's  Gas  and  Oil  Engine T Small  8vo,    4  oo 

Coolidge's  Manual  of  Drawing 8vo,  paper,     i  oo 

Coolidge  and  Freeman's  Elements  of  General  Drafting  for  Mechanical  En- 
gineers  Oblong  4to,    2  50 

11 


Cromwell's  Treatise  on  Toothed  Gearing i2mo,  i  50 

Treatise  on  Belts  and  Pulleys i2mo,  i  50 

Dur ley V Kinematics  of  Machines 8vo,  4  oo 

Flather's  Dynamometers  and  the  Measurement  of  Power. i2mo,  3  oo 

Rope  Driving xamo,  2  oo 

Gill's  Gas  and  Fuel  Analysis  for  Engineers i2mo,  i  25 

Hall's  Car  Lubrication I2mo,  i  oo 

Bering's  Ready  Reference  Tables  (Conversion  Factors) i6mo,  morocco,  2  50 

Button's  The  Gas  Engine 8vo,  5  oo 

Jamison's  Mechanical  Drawing 8vo,  2  50 

Jones's  Machine  Design: 

Part  I.     Kinematics  of  Machinery 8vo,  i  50 

Part  II.     Form,  Strength,  and  Proportions  of  Parts 8vo,  3  oo 

Kent's  Mechanical  Engineers'  Pocket-book i6mo,  morocco,  5  oo 

Kerr's  Power  and  Power  Transmission 8vo,  2  oo 

Leonard's  Machine  Shop,  Tools,  and  Methods 8vo,  4  oo 

*Lorenz's  Modern  Refrigerating  Machinery.     (Pope,  Haven,  and  Dean.)  .  .8vo,  4  oo 

MacCord's  Kinematics;   or,  Practical  Mechanism 8vo,  5  oo 

Mechanical  Drawing -. 4to,  4  oo 

Velocity  Diagrams 8vo,  i  50 

Mahan's  Industrial  Drawing.     (Thompson.) 8vo,  3  50 

Poole  s  Calorific  Power  of  Fuels 8vo,  3  oo 

Reid's  Course  in  Mechanical  Drawing 8vo,  2  oo 

Text-book  of  Mechanical  Drawing  and  Elementary  Machine  Design. 8vo,  3  oo 

Richard's  Compressed  Air i2mo,  i  50 

Robinson's  Principles  of  Mechanism 8vo,  3  oo 

Schwamb  and  Merrill's  Elements  of  Mechanism 8vo,  3  oo 

Smith's  Press-working  of  Metals 8vo,  3  oo 

Thurston's   Treatise   on   Friction  and   Lost   Work   in   Machinery  and   Mill 

Work -. 8vo,  3  oo 

Animal  as  a  Machine  and  Prime  Motor,  and  the  Laws  of  Energetics .  i2mo,  i  oo 

Warren's  Elements  of  Machine  Construction  and  Drawing 8vo,  7  50 

Weisbach's    Kinematics    and    the    Power    of    Transmission.     (Herrmann — 

Klein.) 8vo,  3  oo 

Machinery  of  Transmission  and  Governors.     (Herrmann — Klein.).  .8vo,  5  oo 

Wolff's  Windmill  as  a  Prime  Mover 8vo,  3  oo 

Wood's  Turbines 8vo,  2  so 


MATERIALS   OF    ENGINEERING. 

Bovey's  Strength  of  Materials  and  Theory  of  Structures 8vo,  7  50 

Burr's  Elasticity  and  Resistance  of  the  Materials  of  Engineering.    6th  Edition. 

Reset 8vo,  7  50 

Church's  Mechanics  of  Engineering , 8vo,  6  oo 

Johnson's  Materials  of  Construction 8vo,  6  oo 

Keep's  Cast  Iron 8vo,  2  50 

Lanza's  Applied  Mechanics 8vo,  7  50 

Martens's  Handbook  on  Testing  Materials.     (Henning.) 8vo,  7  50 

Merriman's  Mechanics  of  Materials.  8vo,  5  oo 

Strength  of  Materials I2mo,  i  oo 

Metcalf's  Steel     A  manual  for  Steel-users. I2mo.  2  eo 

Sabin's  Industrial  and  Artistic  Technology  of  Paints  and  Varnish 8vo,  3  oo 

Smith's  Materials  of  Machines I2mo,  i  oo 

Thurston's  Materials  of  Engineering 3  vols.,  8vo,  8  oo 

Part  II.     Iren  and  Steel : 8vo,  3  5<> 

Part  HI.     A  Treatise  on  Brasses,  Bronzes,  and  Other  Alloys  and  their 

Constituents 8vo,  2  50 

Text-book  of  the  Materials  of  Construction. 8vo,  5  <*> 

12 


Wood's  (De  V.)  Treatise  on  the  Resistance  of  Materials  and  an  Appendix  on 

the  Preservation  of  Timber 8vo,    2  oo 

"Wood's  (De  V.)  Elements  of  Analytical  Mechanics 8vo,    3  oo 

Wood's  (M.  P.)  Rustless  Coatings:    Corrosion  and  Electrolysis  of  Iron  and 

Ste«L 8vo,    4  06 


STEAM-ENGINES  AND  BOILERS. 


Berry's  Temperature-entropy  Diagram i2mc,  i  25 

Carnot's  Reflections  on  the  Motive  Power  ef  Heat.     (Thurston.) i2mo,  i  50 

Dawson's  "Engineering"  and  Electric  Traction  Pocket-book.  .  .  .i6mo,  mor.,  5  oo 

Ford's  Boiler  Making  for  Boiler  Makers i8mo,  i  oo 

Goss's  Locomotive  Sparks 8vo,  2  oo 

Hemenway's  Indicator  Practice  and  Steam-engine  Economy i2mo,  2  oo 

Button's  Mechanical  Engineering  of  Power  Plants 8vo,  5  oo 

Heat  and  Heat-engines 8vo,  5  oo 

Kent's  Steam  boiler  Economy 8vo,  4  oo 

Kneass's  Practice  and  Theory  of  the  Injector 8vo,  i  50 

MacCord's  Slide-valves „ 8vo,  2  oo 

Meyer's  Modern  Locomotive  Construction 4to,  10  oo 

Peabody's  Manual  of  the  Steam-engine  Indicator i2mo.  i  50 

Tables  of  the  Properties  of  Saturated  Steam  and  Other  Vapors 8vo,  i  oo 

Thermodynamics  of  the  Steam-engine  and  Other  Heat-engines 8vo,  5  oo 

Valve-gears  for  Steam-engines 8vo,  2  50 

Peabody  and  Miller's  Steam-boilers 8vo,  4  oo 

Pray's  Twenty  Years  \vith  the  Indicator Large  8vo,  2  50 

Pupin's  Thermodynamics  of  Reversible  Cycles  in  Gases  and  Saturated  Vapors. 

(Osterberg.) i2mo,  i  25 

Reagan's  Locomotives:  Simple   Compound,  and  Electric i2mo,  2  50 

Rontgen's  Principles  of  Thermodynamics.     (Du  Bois.) 8vo,  5  oo 

Sinclair's  Locomotive  Engine  Running  and  Management i2mo,  2  oo 

Smart's  Handbook  of  Engineering  Laboratory  Practice i2mo,  2  50 

Snov/'s  Steam-boiler  Practice 8vo,  3  oo 

Spangler's  Valve-gears 8vo,  2  50 

Notes  on  Thermodynamics i2mo,  i  oo 

Spangler,  Greene,  and  Marshall's  Elements  of  Steam-engineering 8vo,  3  oo 

Thurston's  Handy  Tables 8vo,  i  50 

Manual  of  the  Steam-engine 2  vols.,  8vo,  10  oo 

Part  I.     History,  Structure,  and  Theory 8vo,  6  oo 

Part  II.     Design,  Construction,  and  Operation 8vo,  6  oo 

Handbook  of  Engine  and  Boiler  Trials,  and  the  Use  of  the  Indicator  and 

the  Prony  Brake 8vo,  5  oo 

Stationary  Steam-engines 8vo,  2  50 

Steam-boiler  Explosions  in  Theory  and  in  Practice i2mo,  i  50 

Manual  of  Steam-boilers,  their  Designs,  Construction,  and  Operation 8vo,  .5  oo 

Weisbach's  Heat,  Steam,  and  Steam-engines.     (Du  Bois.) 8vo,  5  oo 

Whitham's  Steam-engine  Design 8vo,  5  oo 

Wilson's  Treatise  on  Steam-boilers.     (Flather.) i6mo,  2  50 

Wood's  Thermodynamics,  Heat  Motors,  and  Refrigerating  Machines.  .  .8vo,  4  oo 


MECHANICS  AND  MACHINERY. 

Barr's  Kinematics  of  Machinery 8vo,  2  50 

Bovey's  Strength  of  Materials  and  Theory  of  Structures 8vo,  7  50 

Chase's  The  Art  of  Pattern-making , i2mo,  2  50 

Churches  Mechanics  of  Engineering 8vo,  6  oo 

IS 


Church's  Notes  and  Examples  in  Mechanics 8vo,  2  oo 

Compton's  First  Lessons  in  Metal-working i2mo,  50 

Compton  and  De  Groodt's  The  Speed  Lathe i2mo,  50 

Cromwell's  Treatise  on  Toothed  Gearing i2mo,  50 

Treatise  on  Belts  and  Pulleys i2mo,  50 

Dana's  Text-book  of  Elementary  Mechanics  for  Colleges  and  Schools.  . i2mo,  50 

Dingey's  Machinery  Pattern  Making i2mo,  oo 

Dredge's  Record  of  the  Transportation  Exhibits  Building  of  the   World's 

Columbian  Exposition  of  1893 4to  half  morocco,  5  oo 

Du  Bois's  Elementary  Principles  of  Mechanics : 

Vol.      I.     Kinematics 8vo,  3  50 

VoL    II.     Statics 8vo,  4  oo 

VoL  in.     Kinetics 8vo,  3  50 

Mechanics  of  Engineering.     VoL    I Small  4to,  7  50 

VoL  n Small  4to,  10  oo 

Durley's  Kinematics  of  Machines 8vo,  4  oo 

Fitzgerald's  Boston  Machinist i6mo,  i  oo 

Flather's  Dynamometers,  and  the  Measurement  of  Power i2mo,  3  oo 

Rope  Driving i2mo,  2  oo 

Goss's  Locomotive  Sparks 8vo,  2  oo 

Hall's  Car  Lubrication i2mo,  i  oo 

Holly's  Art  of  Saw  Filing i8mo,  75 

James's  Kinematics  of  a  Point  and  the  Rational  Mechanics  of  a  Particle.  Sm  .8vc,2  oo 

*  Johnson's  (W.  W.)  Theoretical  Mechanics i2mo,  3  oo 

Johnson's  (L.  J.)  Statics  by  Graphic  and  Algebraic  Methods 8vo,  2  oo 

Jones's  Machine  Design: 

Part    I.     Kinematics  of  Machinery 8vo,  i  50 

Part  n.     Form,  Strength,  and  Proportions  of  Parts 8vo,  3  oo 

Kerr's  Power  and  Power  Transmission 8vo,  2  oo 

Lanza's  Applied  Mechanics 8vo,  7  50 

Leonard's  Machine  Shop,  Tools,  and  Methods 8vo,  4  oo 

*Lorenz's  Modern  Refrigerating  Machinery.      (Pope,  Haven,  and  Dean.). 8vo,  4  oo 

MacCord's  Kinematics;  or,  Practical  Mechanism 8vo,  5  oo 

Velocity  Diagrams 8vo,  i  50 

Maurer's  Technical  Mechanics 8vo,  4  oo 

Merriman's  Mechanics  of  Materials 8vo,  5  oo 

*  Elements  of  Mechanics i2mo,  i  oo 

*  Michie's  Elements  of  Analytical  Mechanics 8vo,  4  oo 

Reagan's  Locomotives:   Simple,  Compound,  and  Electric i2mo>  2  50 

Reid's  Course  in  Mechanical  Drawing 8vo,  2  oo 

Text-book  of  Mechanical  Drawing  and  Elementary  Machine  Design. 8vo,  3  oo 

Richards's  Compressed  Air i2mo,  i  50 

Robinson's  Principles  of  Mechanism 8vo,  3  oo 

Ryan,  Norris,  and  Hoxie's  Electrical  Machinery.     VoL  1 8vo,  2  50 

Schwamb  and  Merrill's  Elements  of  Mechanism 8vo,  3  oo 

Sinclair's  Locomotive-engine  Running  and  Management I2mo,  2  oo 

Smith's  (0.)  Press-working  of  Metals 8vo,  3  oo 

Smith's  (A.  W.)  Materials  of  Machines I2mo,  i  oo 

Spangler,  Greene,  and  Marshall's  Elements  of  Steam-engineering 8vo,  3  oo 

Thurston's  Treatise  on  Friction  and  Lost  Work  in    Machinery  and    Mill 

Work 8vo,  3  oo 

Animal  as  a  Machine  and  Prime  Motor,  and  the  Laws  of  Energetics. 

i2mo,  i  oo 

Warren's  Elements  of  Machine  Construction  and  Drawing 8vo,  7  50 

Weisbach's  Kinematics  and  Power  of  Transmission.   ( Herrmann — Klein. ) .  8vo ,  5  oo 

Machinery  of  Transmission  and  Governors.      (Herrmann — Klein.).8vo,  5  oo 

Wood's  Elements  of  Analytical  Mechanics 8vo,  3  oo 

Principles  of  Elementary  Mechanics I2mo,  i  25 

Turbines 8vo,  2  50 

The  World's  Columbian  Exposition  of  1893 4to,  I  oo 

14 


METALLURGY. 

Egleston's  Metallurgy  of  Silver,  Gold,  and  Mercury: 

Vol.    L     Silver 8vo,  7  So 

Vol.  II.     Gold  and  Mercury. : 8vo,  7  50 

**  Iles's  Lead-smelting.     (Postage  9  cents  additional.). i2mo,  2  50 

Keep's  Cast  Iron 8vo,  2  50 

Kunhardt's  Practice  of  Ore  Dressing  in  Europe 8vo,  i  50 

Le  Chatelier's  High-temperature  Measurements.  (Boudouard — Burgess.  )i2mo,  3  oo 

Metcalf's  Steel.     A  Manual  for  Steel-users-     i2mo,  2  oo 

Smith's  Materials  of  Machines i2mo,  i  oo 

Thurston's  Materials  of  Engineering.     In  Three  Parts 8vo.  8  oo 

Part    H.     Iron  and  Steel 8vo,  3  50 

Part  III.     A  Treatise  on  Brasses,  Bronzes,  and  Other  Alloys  and  their 

Constituents 8vo,  2  50 

Hike's  Modern  Electrolytic  Copper  Refining 8vo,  3  oo 

MINERALOGY. 

Barringer's  Description  of  Minerals  of  Commercial  Value.    Oblong,  morocco,  2  50 

Boyd's  Resources  of  Southwest  Virginia 8vo,  3  oo 

Map  of  Southwest  Virignia Pocket-book  form.  2  oo 

Brush's  Manual  of  Determinative  Mineralogy.     (Penfield.) 8vo,  4  oo 

Chester's  Catalogue  of  Minerals 8vo,  paper,  i  oo 

Cloth,  i  25 

Dictionary  of  the  Names  of  Minerals 8vo,  3  50 

Dana's  System  of  Mineralogy Large  8vo,  half  leather,  12  50 

First  Appendix  to  Dana's  New  "  System  of  Mineralogy." Large  8vo,  i  oo 

Text-book  of  Mineralogy 8vo,  4  oo 

Minerals  and  How  to  Study  Them i2mo,  i  50 

Catalogue  of  American  Localities  of  Minerals Large  8vo,  i  oo 

Manual  of  Mineralogy  and  Petrography i2mo,  2  oo 

Douglas's  Untechnical  Addresses  on  Technical  Subjects 12010,  i  oo 

Eakle's  Mineral  Tables 8vo,  i  25 

Egleston's  Catalogue  of  Minerals  and  Synonyms 8vo,  2  50 

Hussak's  The  Determination  of  Rock-forming  Minerals.    (Smith. ).  Small  8vo,  2  oo 

Merrill's  Non-metallic  Minerals:  Their  Occurrence  and  Uses 8vo,  4  oo 

*  Penfield's  Notes  on  Determinative  Mineralogy  and  Record  of  Mineral  Tests. 

8vo  paper,  o  50 
Rosenbusch's   Microscopical  Physiography   of   the   Rock-making  Minerals. 

(Iddings.) 8vo.  5  oo 

*  Tillman's  Text-book  of  Important  Minerals  and  Rocks ,  .8vo.  2  oo 

Williams's  Manual  of  Lithology 8vo,  3  oo 

MINING. 

Beard's  Ventilation  of  Mines I2mo.  2  50 

Boyd's  Resources  of  Southwest  Virginia 8vo.  3  oo 

Map  of  Southwest  Virginia Pocket  book  form,  2  oo 

Douglas's  Untechnical  Addresses  on  Technical  Subjects i2mo.  i  oo 

*  Drinker's  Tunneling,  Explosive  Compounds,  and  Rock  Drills.  -4to,hf.  mor. .  25  oo 

Eissler's  Modern  High  Explosives 8vo,  4  oo 

Fowler's  Sewage  Works  Analyses 12010,  2  oo 

Goodyear's  Coal-mines  of  the  Western  Coast  of  the  United  States i2mo.  2  50 

Ihlseng's  Manual  of  Mining , .8vo»  5  oo 

**  Iles's  Lead-smelting.     (Postage  pc.  additional.) i2mo.  50 

Kunhardt's  Practice  of  Ore  Dressing  in  Europe , .8vo,  50 

O'Driscoll's  Notes  on  the  Treatment  of  Gold  Ores 8vo,  oo 

*  Walke's  Lectures  on  Explosives 8vo,  oo 

Wilson's  Cyanide  Processes I2mo>,  50 

Chlorination  Process I2ino,  50 

15 


Wilson's  Hydraulic  and  Placer  Mining i2mo,  2  oo 

Treatise  on  Practical  and  Theoretical  Mine  Ventilation «  .  .  .  T2mo,  i  25 

SANITARY  SCIENCE. 

Bashore's  Sanitation  of  a  Country  House I2mo,  i  oo 

Folwell's  Sewerage.     (Designing,  Construction,  and  Maintenance.) 8vo^  3  oc 

Water-supply  Engineering 8vo,  4  oo 

Fuertes's  Water  and  Public  Health. i2mo,  i  50 

Water-filtration  Works I2mo,  2  50 

Gerhard's  Guide  to  Sanitary  House-inspection i6mo,  i  oo 

Goodrich's  Economic  Disposal  of  Town's  Refuse Demy  8vo,  3  50 

Hazen's  Filtration  of  Public  Water-supplies 8vo,  3  oo 

Leach's  The  Inspection  and  Analysis  of  Food  with  Special  Reference  to  State 

Control 8vo,  7  50 

Masou's  Water-supply.  (Considered  principally  from  a  Sanitary  Standpoint)  8vo,  4  oo 

Examination  of  Water.     (Chemical  and  Bacteriological.) i2mo,  i  25 

Merriman's  Elements  of  Sanitary  Engineering 8vo,  2  oo 

Ogden's  Sewer  Design i2mo,  2  oo 

Prescott  and  Winslow's  Elements  of  Water  Bacteriology,  with  Special  Refer- 
ence to  Sanitary  Water  Analysis i2mo,  i  25 

*  Price's  Handbook  on  Sanitation I2mo,  i  50 

Richards's  Cost  of  Food.     A  Study  in  Dietaries i2mo,  i  oo 

Cost  of  Living  as  Modified  by  Sanitaiy  Science i2mo,  i  oo 

Richards  and  Woodman's  Air,  Water,  and  Food  from"  a  Sanitary  Stand- 
point  8vo,  2  oo 

*  Richards  and  Williams's  The  Dietary  Computer 8vo,  i  50 

Rideal's  Sewage  and  Bacterial  Purification  of  Sewage 8vo,  3  50 

Turneaure  and  Russell's  Public  Water-supplies 8vo,  5  oo 

Von  Behring's  Suppression  of  Tuberculosis.     (Bolduan.) i2mo,  i  oo 

Whipple's  Microscopy  of  Drinking-water 8vo,  3  50 

Woodhull's  Notes  on  Military  Hygiene i6mo,  i  50 

MISCELLANEOUS. 

De  Fursac's  Manual  of  Psychiatry.  (Rosanoff  and  Collins.).  .  .  .Large  i2mo,  2  50 
Emmons's  Geological  Guide-book  of  the  Rocky  Mountain  Excursion  of  the 

International  Congress  of  Geologists Large  8vo,  i  50 

Ferrel's  Popular  Treatise  on  the  Winds 8vo.  4  oo 

Haines's  American  Railway  Management i2mo,  2  50 

Mott's  Composition,  Digestibility,  and  Nutritive  Value  of  Food.  Mounted  chart,  i  25 

Fallacy  of  the  Present  Theory  of  Sound i6mo,  i  oo 

Ricketts's  History  of  Rensselaer  Polytechnic  Institute,  1824-1894.. Small  8vo,  3  oo 

Rostoski's  Serum  Diagnosis.  (Bolduan.) i2mo.  i  oo 

Rotherham's  Emphasized  New  Testament Large  8vo,  2  oo 

Steel's  Treatise  on  the  Diseases  of  the  Dog 8vo,  3  50 

Totten's  Important  Question  in  Metrology 8vo,  2  50 

The  World's  Columbian  Exposition  of  1893 4to,  i  oo 

Von  Behring's  Suppression  of  Tuberculosis.  (Bolduan.) i2mo,  i  oo 

Winslow's  Elements  of  Applied  Microscopy i2mo,  i  50 

Worcester  and  Atkinson.  Small  Hospitals,  Establishment  and  Maintenance; 

Suggestions  for  Hospital  Architecture :  Plans  for  Small  Hospital .  1 2mo ,  125 

HEBREW  AND  CHALDEE  TEXT-BOOKS. 

Green's  Elementary  Hebrew  Grammar i2mo,  i  25 

Hebrew  Chrestomathy 8vo,  3  oo 

Gesenius's  Hebrew  and  Chaldee  Lexicon  tr   the  Old  Testament  Scriptures. 

(Tregelles.) Small  4to,  half  morocco,  5  oo 

Letter's  Hebrew  Bible 8vo»  »  2S 

16 


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